Ultra-Stable High-Finesse Cavity

Catalog 2024

Optical Components & Technical Capabilities

Imprint

Edition:2nd Edition, © LAYERTEC, 2024, January

Phone:
E-mail:Internet:
Fax:+49 36453 744 0
info@layertec.de
www.layertec.de+49 36453 744 40

Phone (US):E-mail (US):+1 707 48 10 216
ussales@layertec.com

Location:

LAYERTEC GmbH
Ernst-Abbe-Weg 1
99441 Mellingen
GERMANY

Images:LAYERTEC GmbH

New: Ultra-Stable High-Finesse Cavity
This assembly consists of two highly reflective mirrors made of Fused Silica or ULE, which
are coated using sputtering techniques. The mirrors are manufactured according to customer requirements (wavelengths, reflectance, transmittance). Typically, the resonator optics achieve reflection values of 99.999 % at a wavelength of 1540 nm and 99.998 % at
700 nm with a transmittance of 5 ppm. The optical components are connected to a spacer
made of ULE, which is also manufactured according to customer specifications (geometry,material, etc.). At 1540 nm we guarantee a finesse of 250,000 – 300,000. The mirrors arejoined to the cavity by optical contacting and laser welding without any additives. Laserwelding guarantees high mechanical stability of the cavity.

2

Introduction
WelcomeIntroduction
WelcomeLAYERTEC is a globally recognized producer of optical components.
The main focus is on the commercial production of high-performance optics for laser applications in the wavelength range 125 nm to
8 µm, including large scale optics.
LAYERTEC is able to manufacture complex components as single pieces or in series and offers the complete manufacturing chain:• Precision optics manufacturing of flat, spherical, aspherical and cylindrical surfaces from 1 to 2000 mm edge length• Metallic, fluoridic and oxidic coatings with evaporation and sputtering technologies• Structuring of optical coatings• Joining services• Laser engraving• Ultrasonic-machined glass substrates (weight reduction, drillings)• Extensive optical metrology for quality control
LAYERTEC is certified according to DIN EN ISO 9001-2015.

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Figure 1: LAYERTEC’s technical manufacturing capabilities

1Introduction
Table of Contents

Table of Contents
Introduction........................................................................................................................................................................... 1
Welcome..............................................................................................................................................................................................1
Table of Contents.................................................................................................................................................................................2

Optical Coatings

4

Selection of Optical Components for Common Laser Types.................................................................................................... 4
F2 Lasers (157 nm)................................................................................................................................................................................5
ArF Lasers (193 nm).............................................................................................................................................................................7
KrF, XeCl, XeF Lasers (248 nm, 308 nm, 351 nm).................................................................................................................................9
Ruby and Alexandrite Lasers (694 nm, 755 nm)..................................................................................................................................12
Ti:Sapphire Lasers operated with ns-Pulses (550 – 1100 nm)..............................................................................................................14
Diode Lasers (620 – 680 nm, 808 – 990 nm)......................................................................................................................................16
High Power Lasers on the Basis of Yb- and Nd-doped Materials (1020 – 1080 nm)............................................................................18
Second Harmonic of High Power Lasers on the Basis of Yb- and Nd-doped Materials (515 nm, 532 nm)............................................21
Third Harmonic of High Power Lasers on the Basis of Yb- and Nd-doped Materials (343 nm, 355 nm)...............................................23
Higher Harmonics of High Power Lasers on the Basis of Yb- and Nd-doped Materials (213 nm, 266 nm)............................................25
Weak Nd:YAG or Nd:YVO4 Laser Lines (915 nm, 946 nm, 1123 nm, 1340 nm)..................................................................................27
Ho:YAG and Tm:YAG Lasers (2010 nm, 2100 nm)..............................................................................................................................29
Er:YAG Lasers and the 3 µm Region...................................................................................................................................................32
Ultrafast Laser Optics........................................................................................................................................................... 34
Introduction to Ultrafast Laser Optics.................................................................................................................................................35
Standard Ultrafast Laser Optics (120 – 150 nm Bandwidth)................................................................................................................37
Broadband Ultrafast Laser Optics (200 – 300 nm Bandwidth).............................................................................................................44
Octave Spanning Ultrafast Laser Optics (400 – 500 nm Bandwidth)....................................................................................................49
Silver Mirrors for Ultrafast Lasers (550 – 1100 nm).............................................................................................................................52
High Power Ultrafast Laser Optics (550 – 1100 nm)............................................................................................................................54
Components for the Second Harmonic of the Ti:Sapphire Laser (300 – 600 nm).................................................................................57
Components for the Third Harmonic of the Ti:Sapphire Laser (250 – 400 nm)....................................................................................60
Components for the Higher Harmonics of the Ti:Sapphire Laser (140 – 250 nm)................................................................................62
Gires-Tournois-Interferometer (GTI) Mirrors (600 – 1600 nm)..............................................................................................................64
Optics for Ultrafast Lasers in the Wavelength Range of 1000 – 1600 nm............................................................................................67
Selected Special Components............................................................................................................................................... 70
Components for Optical Parametric Oscillators (OPO).........................................................................................................................71
Broadband and Scanning Mirrors (300 – 2500 nm)............................................................................................................................76
Filters for Laser Applications (260 – 2500 nm)....................................................................................................................................78
Thin Film Polarizers.............................................................................................................................................................................80
Low Loss Optical Components (340 – 3000 nm).................................................................................................................................82
Coatings on Crystal Optics (340 – 3000 nm).......................................................................................................................................84
Metallic Coatings................................................................................................................................................................. 86
Front Surface Silver Mirrors (400 – 4000 nm)......................................................................................................................................87
Front Surface Aluminum Mirrors (150 – 900 nm)................................................................................................................................90
Special Metallic Coatings (400 – 10 000 nm)......................................................................................................................................93

Standard Catalog

95Standard Items from Stock................................................................................................................................................... 95Standard Items from Stock.................................................................................................................................................................97
Specifications of Plane Substrates.......................................................................................................................................................98
Specifications of Curved Substrates..................................................................................................................................................100
Excimer Lasers [193 nm, 248 nm, 308 nm]........................................................................................................................................102
fs-Laser [TiSa, up to 150 nm bandwidth]...........................................................................................................................................104
fs-Laser [TiSa, 300 nm bandwidth]....................................................................................................................................................109
ps/fs-Laser [1030–1040 nm]..............................................................................................................................................................113
cw/ns-Laser [1030–1064 nm]............................................................................................................................................................117
2 μm [Ho:YAG | Tm:YAG]...................................................................................................................................................................123
3 μm [Er:YAG]...................................................................................................................................................................................125
Metallic Mirrors................................................................................................................................................................................127
Low Loss Mirrors for CRD-Measurements ........................................................................................................................................129
Low Loss Mirror Set for High Finesse Cavities ..................................................................................................................................130
Beam Expanders...............................................................................................................................................................................132

2

Introduction
Table of Contents

Technology

133

Precision Optics.................................................................................................................................................................. 133
How to Specify Substrates................................................................................................................................................................134
Standard Quality Substrates..............................................................................................................................................................136
Substrate Materials..........................................................................................................................................................................138
Optical Fabrication Methods............................................................................................................................................................142
Measurement Tools for Testing Substrates........................................................................................................................................152
Optical Coatings................................................................................................................................................................. 156
Coating Technologies.......................................................................................................................................................................157
Optical Interference Coatings...........................................................................................................................................................160
Metallic Coatings.............................................................................................................................................................................166
Metal-Dielectric Coatings.................................................................................................................................................................167
Measurement Tools for Optical Coatings..........................................................................................................................................168
Specials.............................................................................................................................................................................. 176
Solderable Coatings..........................................................................................................................................................................177
Lithography......................................................................................................................................................................................178
Optical Assemblies...........................................................................................................................................................................179
Laser Engraving................................................................................................................................................................................181

Knowhow

182

Knowhow.......................................................................................................................................................................... 182
Polarization......................................................................................................................................................................................183
Dielectric Mirrors – Non-Normal Incidence.......................................................................................................................................184
Weakly Curved Substrates................................................................................................................................................................185
Surface Form Tolerances ..................................................................................................................................................................186
Surface Imperfection Tolerances.......................................................................................................................................................187
Laser-Induced Damage Threshold (LIDT)...........................................................................................................................................188
Group Delay Distortion (GD & GDD).................................................................................................................................................189
How to Mount Optics......................................................................................................................................................................190
Cleaning of Optical Surfaces.............................................................................................................................................................191

Company

192

Company............................................................................................................................................................................ 192
History.............................................................................................................................................................................................193
General Terms and Conditions of Sale (Effective 01/04/2016)...........................................................................................................197
Payment and Shipment....................................................................................................................................................................202
Imprint.............................................................................................................................................................................................203

3

Selection of Optical Components for Common Laser Types

Selection of Optical
Components for Common
Laser Types
Chapter Index
F2 Lasers (157 nm)..............................................................5
Mirrors.....................................................................................5
Output Couplers.......................................................................5
Aluminum Mirrors for F2 Lasers................................................6
Technical Data of Standard F2 Laser Components.....................6
Components for the Fifth and Sixth Harmonic of
Ti:Sapphire Lasers.....................................................................6
ArF Lasers (193 nm)............................................................7
Mirrors.....................................................................................7
Output Couplers.......................................................................7
Aluminum Mirrors....................................................................8
Technical Data of Standard ArF Laser Components...................8
Components for the Fourth Harmonic of Ti:Sapphire Lasers.....8
KrF, XeCl, XeF Lasers (248 nm, 308 nm, 351 nm)................9
Cavity Mirrors...........................................................................9
Fluorine Resistant Cavity Mirrors...............................................9
Output Couplers.......................................................................9
Fluorine Resistant Output Couplers.........................................10
Windows and Lenses..............................................................10
Turning Mirrors......................................................................10
Attenuators............................................................................11
LIDT and Lifetime Data...........................................................11
Ruby and Alexandrite Lasers (694 nm, 755 nm)................12
Cavity Mirrors.........................................................................12
Turning Mirrors......................................................................12
Beam Combiners....................................................................13
Output Couplers.....................................................................13
Ti:Sapphire Lasers operated with ns-Pulses(550 – 1100 nm)................................................................14
Cavity Mirrors.........................................................................14
Pump Mirrors.........................................................................14
Turning Mirrors......................................................................15
Output Couplers.....................................................................15
Diode Lasers (620 – 680 nm, 808 – 990 nm).....................16
Turning Mirrors......................................................................16
Scanning Mirrors....................................................................16
Thin Film Polarizers.................................................................16
Conventional Steep Edge Combiners for Diode Lasers............17
Special Steep Edge Combiners for Unpolarized Light..............17

4

High Power Lasers on the Basis of
Yb- and Nd-doped Materials (1020 – 1080 nm)................18
Mirrors...................................................................................18
Edge Filters and Pump Mirrors................................................18
Thin Film Polarizers.................................................................19
Picosecond Lasers based on Yb-doped Materials....................19
Alignment and Process Monitoring.........................................20
Beam Splitters and Output Couplers.......................................20
Non Polarizing Beam Splitters.................................................20

Second Harmonic of High Power Lasers on the Basis of
Yb- and Nd-doped Materials (515 nm, 532 nm)................21
Dual Wavelength Turning Mirror............................................21
Dual Wavelength Cavity Mirror...............................................21
Separators for the Second Harmonic and theFundamental Wave................................................................21
Thin Film Polarizers.................................................................22
Non-Polarizing Beam Splitters.................................................22
Coating on Nonlinear Optical Crystals....................................22
Third Harmonic of High Power Lasers on the Basis of
Yb- and Nd-doped Materials (343 nm, 355 nm)................23
Standard Components............................................................23
Turning Mirrors......................................................................23
Standard Separators...............................................................23
Special Separators..................................................................23
Windows and Lenses..............................................................24
Sputtered Multiple Wavelength Mirrors..................................24
Sputtered Thin Film Polarizers.................................................24
Higher Harmonics of High Power Lasers on the Basisof Yb- and Nd-doped Materials (213 nm, 266 nm)............25
Multiple Wavelength Mirrors..................................................25
Separators for the Fourth Harmonic.......................................25
Separators for the Fifth Harmonic...........................................25
Special Separators..................................................................26
Thin Film Polarizers.................................................................26
Weak Nd:YAG or Nd:YVO4 Laser Lines(915 nm, 946 nm, 1123 nm, 1340 nm)..............................27
Ho:YAG and Tm:YAG Lasers (2010 nm, 2100 nm).............29
Cavity Mirrors.........................................................................29
Turning Mirrors......................................................................29
Output Couplers.....................................................................30
Edge Filters............................................................................30
Thin Film Polarizers.................................................................30
Windows and Lenses..............................................................31
Er:YAG Lasers and the 3 µm Region..................................32
Cavity Mirrors.........................................................................32
Pump Mirrors.........................................................................32
Turning Mirrors......................................................................32
Beam Combiners and Alignment Laser Mirrors.......................33
Output Couplers and Lenses...................................................33

Selection of Optical Components for Common Laser Types
F2 Lasers (157 nm)

F2 Lasers (157 nm)• High quality mirror substrates, windows and lenses of CaF2
(193 nm excimer grade quality, HELLMA Materials GmbH)• Please note that the 157 nm excimer grade CaF2 can nolonger be offered. The market for this kind of material is too
small compared to the huge effort necessary for the crystal
manufacturers to test the material according to this quality
standard. Thus, all LAYERTEC optics for F2 lasers will be manufactured using 193 nm excimer grade material in the future.

• PR coatings with tolerances of:± 2 % for R = 10 % … 30 %± 3 % for R = 30 % … 75 %and ± 2 % for R = 75 % … 90 %• Development and production of customer specific components like beam splitters and variable attenuators on request

Mirrors
Measurement
100
90
80
70
60
50
40
30
20
10
0

R

T

AOI = 0°b

R, T [%]

R, T [%]

a

130

150

170

190

210

230

wavelength [nm]Measurement
100
90
80
70
60
50
40
30
20
10
0

130

150

Rs

170

Ts

190

Rp

Tp

AOI = 45°

210

230

wavelength [nm]Figure 1: Measured reflectance and transmittance spectra of mirrors for 157 nma) Laser mirror (AOI = 0°)b) Turning mirror (AOI = 45°)

• Laser mirrors:
R = 92 % … 95 % at AOI = 0°

• Turning mirrors (AOI = 45°):
Rs > 95 %Rp > 90 %Ru > 92 %Output Couplers
Measurement

R = 25 ±2 %

130

170

R = 50 ±3 %AOI = 0°

210

230

60
50

R [%]

40
30
20
10
0

150

190

wavelength [nm]Figure 2: Measured reflectance spectra of standard output couplers with:
R = 50 % ± 3 % and R = 25 % ± 2 % (rear side uncoated)

5

Selection of Optical Components for Common Laser Types
F2 Lasers (157 nm)

Aluminum Mirrors for F2 Lasers
Measurement
100
90
80
70
60
50
40
30
20
10
0

AOI = 0°

b

R [%]

R [%]

a

120

140

160

180

200

220

Measurement
100
90
80
70
60
50
40
30
20
10
0

120

AOI = 0°140160

wavelength [nm]

180

200

220

wavelength [nm]Figure 3: Reflectance spectra of aluminum mirrorsa) Protected aluminum mirrorb) Enhanced aluminum mirror for 157 nm• Protected aluminum mirrors (optimized for 157 nm): R = 74 % … 78 %• Dielectrically enhanced aluminum mirrors: up to R = 94 % at AOI = 0°
• For more information on aluminum mirrors see page 90 f.

Technical Data of Standard F2 Laser Components
Table 1: Technical Data of Standard F2 Laser Components

Coating

Spectral Performance

Lifetime Tests

HR (0°, 157 nm)

R = 92 % … 95 %2 × 108 – 1 × 109 pulses*

HR (45°, 157 nm)

R = 90 % … 94 % (unpol. light)

PR (0°, 157 nm)

R = 50 % ±3 %2 × 108 – 1 × 109 pulses*

PR (0°, 157 nm)

R = 25 % ±2 %2 × 108 – 1 × 109 pulses*

AR (0°, 157 nm)

R = 0.3 % … 0.7 %*Energy density 25 mJ/cm², repetition rate 800 Hz, pulse duration 15 ns; tested at COHERENT AG, München

Components for the Fifth and Sixth Harmonic of Ti:Sapphire Lasers
Mirrors and separators for the 133 nm and 160 nm range are produced by coating techniques which were developed for F2 laser coatings.
For more information please see page 62 f.

6

Selection of Optical Components for Common Laser Types
ArF Lasers (193 nm)

ArF Lasers (193 nm)
Mirrors
R
100
90
80
70
60
50
40
30
20
10
0
160

T

AOI = 0°b

R, T [%]

R, T [%]

a

170

180

190

200

210

220

230

Measurement
100
90
80
70
60
50
40
30
20
10
0

160

wavelength [nm]

170

R

180

190

200

T

210

AOI = 45°

220

230

wavelength [nm]Figure 1: Reflectance and transmittance spectra of mirrors for 193 nma) Resonator mirror (AOI = 0°)b) Turning mirror (AOI = 45°, unpolarized light)• All fluoride systems guarantee high reflectance and high damage thresholds• High quality mirror substrates, windows and lenses of CaF2 (193 nm excimer grade, HELLMA Materials GmbH) and Fused Silica• Development and production of customer specific components such as beam splitters and variable attenuators on request

Output Couplers
Measurement

PR 50 %PR 25 %

AOI = 0°

60
50

R [%]

40

• Single wavelength AR coating withresidual reflectance values of:
R < 0.25 % at AOI = 0° andR < 0.6 % at AOI = 45° (unpolarized light)

30
20
10
0

• PR coatings with tolerances of:± 2 % for R = 10 % … 30 %± 3 % for R = 30 % … 75 %± 2 % for R = 75 % … 90 %± 1 % for R > 90 %

150

170

190

210

230

250

• Broadband and multiple wavelength AR coatings

wavelength [nm]Figure 2: Reflectance spectra of output couplers withR (0°, 193 nm) = 50 % ± 3 % andR (0°, 193 nm) = 25 % ± 2 % (coated side only)7Selection of Optical Components for Common Laser Types
ArF Lasers (193 nm)

Aluminum Mirrors
Measurement
100
90
80
70
60
50
40
30
20
10
0
130
150

AOI = 0°

b

R [%]

R [%]

a

170

190

210

230

250

Measurement
100
90
80
70
60
50
40
30
20
10
0
130
150

wavelength [nm]

Rs

170

190

Rp

AOI = 45°

210

230

wavelength [nm]Figure 3: Reflectance spectra of aluminum mirrors.
a) Protected aluminum mirror optimized for 193 nmb) Enhanced aluminum mirror for 193 nm, AOI = 45°• Enhanced aluminum mirrors:
Rp > 93 %Rs > 98 %Ru > 96 %For more information on aluminum mirrors see page 90.

Technical Data of Standard ArF Laser Components
Table 1: Technical Data of Standard ArF Laser Components

Coating/Reflectance Fluoride Coating

Substrate

Damage Threshold*

Lifetime Test

AR (0°, 193 nm) R < 0.25 %CaF2

4 – 5 J/cm²

108 pulses, no damage**

AR (0°, 193 nm) R < 0.25 %Fused Silica

2 – 3 J/cm²

PR (0°, 193 nm) R = 25 %CaF2

3 – 4 J/cm²

1010 pulses, no damage**PR (0°, 193 nm) R = 50 %CaF2

2 – 3 J/cm²

1010 pulses**HR (0°, 193 nm) R > 97 %(typically R > 98 %)CaF2

2 – 3 J/cm²

1010 pulses**, no damage
4 × 109 pulses***, no damage

HRu (45°, 193 nm) R > 97 %(typically R > 98 %)CaF2

2 – 3 J/cm²

*
**
***

1000-on-1, pulse duration 14 ns; measurements were performed at Laser Labor Göttingen, Laser Zentrum Hannover and at Friedrich Schiller University Jena
Energy density 55 mJ/cm², repetition rate 1 kHz, pulse duration 15 ns; tested at COHERENT AG, München
Energy density 80 mJ/cm², repetition rate 1 kHz, pulse duration 12 ns; tested at COHERENT AG, München

Components for the Fourth Harmonic of Ti:Sapphire Lasers
Mirrors and separators for the 4th harmonic of Ti:Sapphire lasers in the wavelength range around 200 nm are produced by coating techniques which were developed for ArF laser coatings. For more information please see page 62 f.

8

Selection of Optical Components for Common Laser Types
KrF, XeCl, XeF Lasers (248 nm, 308 nm, 351 nm)

KrF, XeCl, XeF Lasers (248 nm, 308 nm, 351 nm)
Cavity Mirrors

R [%]AOI = 0°
100
99
98
97
96
95
94
93
92
91
90

250

275

300

325

350

• Oxide coatings for high mechanical stability• Coatings can be produced by IAD, magnetron sputteringor IBS

375

wavelength [nm]Figure 1: Reflectance spectrum of a 308 nm cavity mirror

Fluorine Resistant Cavity Mirrors

R [%]AOI = 0°
100
90
80
70
60
50
40
30
20
10
0

• Fluoride coatings and CaF2 substrates for high stability against
fluorine and chlorine• Laser mirrors with R > 98 % at 248 nm, 308 nm and 351 nm

260 270

280

290

300

310

320

330

340

350

360

wavelength [nm]Figure 2: Reflectance spectrum of a fluoride KrF cavity mirror

Output Couplers
AOI = 0°
60
50

R [%]

40

• PR coatings with tolerances of± 2 % for R = 10 % … 30 %± 3 % for R = 30 % … 75 %± 2 % for R = 75 % … 90 %and ± 1 % for R > 90 %

30
20
10
0

270

280

290

300

310

320

330

340

350

wavelength [nm]Figure 3: Reflectance spectrum of an output coupler with R (0°, 308 nm) =50 % ± 3 %9Selection of Optical Components for Common Laser Types
KrF, XeCl, XeF Lasers (248 nm, 308 nm, 351 nm)

Fluorine Resistant Output Couplers
AOI = 0°3025

• PR coatings with tolerances of:± 2 % for R = 10 % … 20 %± 3 % for R = 20 % … 75 %and ± 2 % for R = 75 % … > 90 %

R [%]

20
15
10
5
0
200

210

220

230

240

250

260

270

280

290

300

wavelength [nm]Figure 4: Reflectance spectrum of a fluoride output coupler withR (0°, 248 nm) = 25 % ± 3 %R [%]Windows and Lenses

10
9
8
7
6
5
4
3
2
1
0

AOI = 30°

AOI = 0°

250

270

290

310

330

350

370

390

410

430

• High quality mirror substrates, windows and lenses of Fused
Silica450

wavelength [nm]Figure 5: Reflectance spectra of an AR coating for 308 nm
and AOI = 0° – 30°

Turning Mirrors
Measurement

Rs

Rp

AOI = 45°

R [%]

100.0
99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

280

290

300

310

320

330

wavelength [nm]Figure 6: Reflectance spectra of a turning mirror for 308 nm produced by
IBS (Reflectance measurement in s- and p-polarization by CRDS)
Table 1: Reflectance of Turning Mirror

10

Coating

R (AOI = 0°)

Rs (AOI = 45°)

Rp (AOI = 45°)

248 nm IAD> 99.0 %> 99.5 %> 99.0 %248 nm sputtering> 99.7 %> 99.8 %> 99.6 %308 nm IAD> 99.7 %> 99.8 %> 99.5 %308 nm sputtering> 99.9 %> 99.9 %> 99.7 %351 nm IAD> 99.9 %> 99.9 %> 99.7 %351 nm sputtering> 99.95 %> 99.95 %> 99.9 %Selection of Optical Components for Common Laser Types
KrF, XeCl, XeF Lasers (248 nm, 308 nm, 351 nm)

Attenuators

R, T [%]

R
100
90
80
70
60
50
40
30
20
10
0
250

270

290

310

330

350

T

T (0 – 1 %)AOI = 45°

370

390

430

410

450

wavelength [nm]Figure 7: Transmittance spectrum of a sputtered attenuator for 308 nm
with exactly adjusted and thermally stable transmittance of
T = 0.08 % at AOI = 45° (unpolarized light)

LIDT and Lifetime Data
Table 2: LIDT of Oxide Coatings

Table 3: Lifetime of Fluoride Coatings

Coating

LIDT* [J/cm²]

Coating

Lifetime

HR (0°, 248 nm)
IAD

10 J/cm² (1-on-1)
5 J/cm² (1000-on-1)

HR (0°, 248 nm)

2 × 108 pulses*

HR (45°, 248 nm)
IAD

PR (0°, 248 nm) = 50 %2 × 108 pulses*

10 J/cm² (1-on-1)

AR (0°, 248 nm)

2 × 108 pulses**HR (0°, 308 nm)

2 × 108 pulses**HR (0°, 351 nm)

2 × 108 pulses**PR (0°, 351 nm) = 25 %2 × 108 pulses***

Measurements were performed at Laser Labor Göttingen andat Friedrich-Schiller-University Jena***

Energy density: 100 mJ/cm², repetition rate: 100 Hz, pulse duration:
15 ns; tested at COHERENT AG, München
Energy density: 55 mJ/cm², repetition rate: 100 Hz, pulse duration:
15 ns; tested at COHERENT AG, München11Selection of Optical Components for Common Laser Types
Ruby and Alexandrite Lasers (694 nm, 755 nm)

Ruby and Alexandrite Lasers (694 nm, 755 nm)
Ruby and alexandrite lasers are especially used for medical laser applications and work at 694 nm and 755 nm, respectively. LAYERTEC offers a wide range of laser optics for both wavelengths with high laser-induced damage thresholds and long lifetimes. Besides typical
combinations with wavelengths for the alignment of the optical system (e.g. 694 nm + 633 nm), a special feature of LAYERTEC products
is the variety of combinations with other common wavelengths used for medical applications in the same device, but from different laser
sources (e.g. 532 nm + 694 nm).
The coatings introduced here are optimized for high LIDT values, but not for extreme spectral bandwidth, GD or GDD. Please add a remark
like “for ruby lasers” or “for alexandrite lasers” to your optics inquiry to avoid any mix-up with optics for Ti:Sapphire lasers which may also
be specified for 694 nm or 755 nm but which show significantly lower LIDT values.

Cavity Mirrors
R
100
90
80
70
60
50
40
30
20
10
0

R (99 – 100 %)AOI = 0°

b

R [%]

R [%]

a

500

550

600

650

700

750

800

850

900

R
100
90
80
70
60
50
40
30
20
10
0
600

650

wavelength [nm]700

R (99 – 100 %)

750

800

850

AOI = 0°900

wavelength [nm]Figure 1: Reflectance spectra of cavity mirrors for:a) R (0°, 694 nm) > 99.9 %b) R (0°, 755 nm) > 99.9 %• Reflectance: R > 99.8 % … R > 99.9 % at AOI = 0°
LIDT Info
800 MW/cm², 694 nm, 35 ns

Turning Mirrors
Ru
100
90
80
70
60
50
40
30
20
10
0
500

AOI = 45°

550

600

650

700

750

800

850

900

wavelength [nm]Figure 2: Reflectance spectra of turning mirrors for:a) Ru (45°, 694 nm) > 99.8 % + Ru (45°, 633 nm) > 95 %b) Ru (45°, 755 nm) > 99.8 % + Ru (45°, 633 – 650 nm) > 95 %LIDT Info
800 MW/cm², 694 nm, 35 ns

12

b

R [%]

R [%]

a

100
90
80
70
60
50
40
30
20
10
0

500

600

700

800

wavelength [nm]Ru

AOI = 45°

900

1000

Selection of Optical Components for Common Laser Types
Ruby and Alexandrite Lasers (694 nm, 755 nm)

Beam Combiners
Ru
100
90
80
70
60
50
40
30
20
10
0
600

AOI = 45°

b

R [%]

R [%]

a

620

640

660

680

700

720

740

760

780

800

100
90
80
70
60
50
40
30
20
10
0
450

480

510

540

wavelength [nm]

570

600

630

660

Ru

AOI = 45°

690

720

750

wavelength [nm]Figure 3: Reflectance spectra of special beam combiners for 694 nm and 633 nm:a) PRu (45°, 694 nm) = 99.0 % ±0.3 %+ Ru (45°, 633 nm) < 35 %b) Ru (45°, 630 – 640 nm) > 35 % + Rp (45°, 694 nm) < 0.3 %• Precisely adjusted degree of reflectance by using sputtering technology• Easy combination with alignment beam (e.g. at 635 nm)• High performance and cost-optimized solutions with special designs

Output Couplers
AOI = 0°

R [%]

R [%]

AOI = 0°
50
45
40
35
30
25
20
15
10
5
0
400

500

600

700

800

900

1000

wavelength [nm]Figure 4: Reflectance spectrum of an output coupler for the ruby laser:
PR (0°, 694 nm) = 20 % ± 2 %

100
90
80
70
60
50
40
30
20
10
0
650

675

700

725

750

775

800

825

850

875

900

wavelength [nm]Figure 5: Reflectance spectrum of an output coupler for the alexandrite
laser: PR (0°, 755 nm) = 85 % ± 2 %• Output couplers with precisely adjusted degree of reflectance• AR coatings for a single wavelength with a residual reflectance of R < 0.2 % on the rear side of output couplers as well as on bothsides of lenses and windows made of Fused Silica

13Selection of Optical Components for Common Laser Types
Ti:Sapphire Lasers operated with ns-Pulses (550 – 1100 nm)

Ti:Sapphire Lasers operated with ns-Pulses (550 – 1100 nm)
LAYERTEC offers a wide range of optical components for Ti:Sapphire lasers which operate with ns-pulses. Please note that all of thesecomponents are optimized for smooth group delay (GD) spectra in order to achieve wide tuning ranges. However, these components are
not optimized for group delay dispersion (GDD). Such optics are necessary for fs-pulses and they will be introduced on page 37 ff.
Please note that broadband optics for Ti:Sapphire lasers cannot be used for the radiation of ruby or alexandrite lasers, although they are
specified for 694 nm or 755 nm, respectively. Ruby and alexandrite lasers require special high power coatings. For such special coatingsplease see page 12 f.

Cavity Mirrorsa

AOI = 0°b

AOI = 0°150

GD [fs]

100

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

50
0

550

650

750

850

950

1050

-50

1150

550

650

750

wavelength [nm]

850

950

1050

1150

wavelength [nm]Figure 1: Reflectance and GD-spectra of a broadband laser mirrora) Reflectance vs. wavelengthb) GD vs. wavelength

Pump Mirrors
R
100
90
80
70
60
50
40
30
20
10
0
450

R (99 – 100 %)AOI = 0°b

AOI = 0°150
100

GD [fs]

R [%]

a

50
0

550

650

750

850

950

1050

wavelength [nm]

1150

1250

-50
550

650

750

850
wavelength [nm]Figure 2: Reflectance spectra of a broadband pump mirrora) Reflectance vs. wavelengthb) GD vs. wavelength

Special Features• Very high reflectance of the mirrors: R > 99.9 %, depending on bandwidth R > 99.98 % may also be achieved• Spectral tolerance: ± 1 %• Center wavelength, bandwidth and reflectance of partial reflectors according to customer specification

14

950

1050

1150

Selection of Optical Components for Common Laser Types
Ti:Sapphire Lasers operated with ns-Pulses (550 – 1100 nm)

Turning Mirrors
a

Rs

Rp

AOI = 45°

b

s-pol

p-pol

AOI = 45°

930

1040

1150

100

GD [fs]

80

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

60
40
20

600

700

800

900

1000

1100

1200

0

1300

600

710

820

wavelength [nm]wavelength [nm]Figure 3: Reflectance and GD spectra of a broadband turning mirrora) Reflectance vs. wavelengthb) GD vs. wavelength

Output Couplers
standard
100
99
98
97
96
95
94
93
92
91
90
600

broadband

AOI = 0°

b

R [%]

R [%]

a

700

800

900

1000

1100

1200

AOI = 0°
100
90
80
70
60
50
40
30
20
10
0
600

700

800

wavelength [nm]

900

1000

1100

wavelength [nm]Figure 4: Reflectance spectra of several types of output couplersa) Standard and broadband output couplerb) Output coupler with a special reflectance profile which enables the compensation of the amplification characteristics of the laser; see also:
B. Jungbluth, J. Wueppen, J. Geiger, D. Hoffmann, R. Poprawe: “High Performance, Widely Tunable Ti:Sapphire Laser with Nanosecond Pulses”
in: “Solid State Lasers XV: Technology and Devices”, Proc. of SPIE Vol. 6100, San Jose 2006
Rs
100
90
80
70
60
50
40
30
20
10
0
500

Rp

Ru

AOI = 45°

b

Rs

Rp

AOI = 45°

20
15
GD [fs]

R [%]

a

10
5

600

700

800

900

1000

1100

1200

0

500

600

700

wavelength [nm]

800

900

1000

1100

1200

wavelength [nm]Figure 5: Reflectance and GD spectra of a broadband beam splitter with PRu (45°, 650 – 1050 nm) = 50 % ± 3 %a) Reflectance vs. wavelengthb) GD vs. wavelength

Tolerances• Standard output couplers (120 – 150 nm bandwidth):± 2.5 % for R = 10 … 70 %± 1.5 % for R = 70 … 90 %± 0.75 % for R = 90 … 95 %± 0.5 % for R = 95 … 98 %± 0.25 % for R > 98 %• Broadband output couplers (200 – 600 nm bandwidth):± 3 % for R = 10 … 70 %± 2 % for R = 70 … 90 %± 1 % for R = 90 … 95 %± 0.5 % for R = 95 … 98 %15

Selection of Optical Components for Common Laser Types
Diode Lasers (620 – 680 nm, 808 – 990 nm)

Diode Lasers (620 – 680 nm, 808 – 990 nm)
Diode lasers are widely used for measurement applications, as alignment lasers, for pumping of solid-state lasers and for direct material
processing. Diode lasers do not require external resonator optics and are mostly coupled to fibers. Many applications require high quality
beam steering optics such as beam combiners or scanning mirrors which are shown on the following pages. For more information on pump
mirrors for solid-state lasers and combiners for diode lasers please see also page 18 ff. and 78 f.

Turning Mirrors
Rs

Rp

AOI = 45°

1000

1050

1100 1150

R [%]

100.0
99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

700

750

800

850

900

950

wavelength [nm]Figure 1: Reflectance spectra of a broadband turning mirror which can beused for all diode lasers between 808 nm and 980 nm(AOI = 45°, s- and p-polarization)

Scanning Mirrors
AOI = 22°
100
95
90
85
80
75
70
65
60
55
50

AOI = 58°

AOI = 45°

b

R [%]

R [%]

a

630

640

650

660

670

AOI = 22°
100
99
98
97
96
95
94
93
92
91
90

700

750

800

wavelength [nm]AOI = 58°

AOI = 45°

850

900

950

1000

wavelength [nm]Figure 2: Reflectance spectra of a scanning mirror for diode lasers between 805 and 940 nm combined with R > 50 % between 630 and 670 nm(alignment laser): HRu (22° – 58°, 805 – 940 nm) > 99.3 % + Ru (22° – 58°, 630 – 670 nm) > 50 %a) Wavelength range of the alignment laser (630 – 670 nm)b) Wavelength range of the high power diode laser (808 – 980 nm)• Scanning mirrors with other specifications on request• For more information and examples about scanning mirrors please see page 76 f. and 87 ff.

Thin Film Polarizers
Rp

880 890

900

910

920

930

940

950

960

970

980

wavelength [nm]Figure 3: Reflectance spectra of a thin film polarizer for 940 nm, AOI = 55°

16

Rs

AOI = 55°

R [%]

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0

100
90
80
70
60
50
40
30
20
10
0
900

910

Rs (99 – 100 %)

920

930

940

Rp

950

960

Rp (0 – 1 %)AOI = 45°970

990 1000

980

wavelength [nm]Figure 4: Reflectance spectra of a broadband thin film polarizer
for 940 – 970 nm:
HRs (45°, 940 – 970 nm) > 99.9 %+ Rp (45°, 940 – 970 nm) < 1 %Selection of Optical Components for Common Laser Types
Diode Lasers (620 – 680 nm, 808 – 990 nm)• Thin film polarizers are especially useful for polarization coupling of high power laser diodes• For high power 940 nm radiation we recommend to use SUPRASIL 300®, SUPRASIL 3001/3002® or Corning 7979® as substratematerial because standard Fused Silica shows an absorption band around this wavelength (see page 138 to 140)

Conventional Steep Edge Combiners for Diode Lasers
Ts
100
90
80
70
60
50
40
30
20
10
0
860

Tp

Tu

AOI = 22.5°

b

T [%]

T [%]

a

880

900

920

940

960

980

1000

wavelength [nm]

Ts
100
90
80
70
60
50
40
30
20
10
0

860

880

900

920

Tp

940

Tu

960

AOI = 45°

980

1000

wavelength [nm]Figure 5: Transmittance spectra of conventional steep edge filters HR (980 nm) > 99.9 % + R (915 nm) < 5 % which are used as combiners
for pump laser diodes at 915 nm and 980 nm:a) HRs,p (22.5°, 980 nm) > 99.9 % + Rs,p (22.5°, 915 nm) < 2 %b) HRs,p (45°, 980 nm) > 99.9 % + Rp (45°, 915 nm) < 2 %• At AOI = 22.5° the conventional steep edge filter separates 915 nm and 980 nm for p-, s-, and unpolarized light• To preserve the steep edge at AOI = 45° the radiation must be polarized and only one polarization can be used. For unpolarized lightthe slope of the edge can change significantly.

Special Steep Edge Combiners for Unpolarized Light

T [%]

Ts
100
90
80
70
60
50
40
30
20
10
0

Tp

Tu

AOI = 45°

• Filters of this type can be used as separators or combiners for
s- and p-polarized light even at 45° incidence• The cut-on/cut-off edges for the two polarizations only show
a spectral separation of about 10 nm• Consequently, these filters can be applied as combiners for
unpolarized light of 940 nm and 980 nm diodes at AOI = 45°

880

900

920

940

960

980

1000

1020

wavelength [nm]Figure 6: Transmittance spectra of a special steep edge filter
HRu (45°, 980 nm) > 99.8 % + Ru (45°, 940 nm) < 3 %17Selection of Optical Components for Common Laser Types
High Power Lasers on the Basis of Yb- and Nd-doped Materials (1020 – 1080 nm)

High Power Lasers on the Basis of
Yb- and Nd-doped Materials (1020 – 1080 nm)
Yb- and Nd-doped high power lasers are commonly used in material processing as well as measurement applications. Thin disk, slab andfiber lasers were developed to achieve high cw-output power and excellent beam quality. They can also be operated as high power lasers
in the ns to fs range.

Mirrors
100
99
98
97
96
95
94
93
92
91
90
900

R

R (99 – 100 %)AOI = 0°

b

R [%]

R [%]

a

950

1000

1050

1100

1150

1200

1250

Rs
100
99
98
97
96
95
94
93
92
91
90
900

950

1000

wavelength [nm]

1050

Rp

1100

Ru

1150

AOI = 45°

1200

1250

wavelength [nm]Figure 1: Reflectance spectra of HR mirrors for 1030 nma) Cavity mirrorb) Turning mirror

LAYERTEC has developed different coating designs for handling extraordinarily high power densities or energy densities in cw lasers or
pulsed lasers, respectively. The designs are optimized either for cw radiation, ns pulses or ps pulses.

Edge Filters and Pump Mirrors
AOI = 0°

R [%]

R [%]

AOI = 0°
100
90
80
70
60
50
40
30
20
10
0

700

800

900

1000

1100

1200

wavelength [nm]Figure 2: Reflectance spectrum of a steep edge short pass filter

1300

100
90
80
70
60
50
40
30
20
10
0
700

800

900

1000

1100

1200

Figure 3: Reflectance spectrum of a steep edge long pass filter
HR (0°, 915 – 980 nm) > 99.8 % + R (0°,1030 – 1200 nm) < 3 %for use as output mirror of a fiber laser (rear side AR coated)

Special Features• Short pass filters with a very steep edge which are utilized as a pump mirror for solid-state lasers based on Yb-doped materials,
e.g. Yb:YAG, Yb:KGW or Yb-doped fiber• Also useful for Nd-doped and Yb-Nd-co-doped materials

18

1300

wavelength [nm]Selection of Optical Components for Common Laser Types
High Power Lasers on the Basis of Yb- and Nd-doped Materials (1020 – 1080 nm)

Thin Film Polarizers
Thin film polarizers are key elements for regenerative amplifiers in ns- and ps-lasers. LAYERTEC optimizes its polarizer designs for highlaser-induced damage thresholds (LIDT). Figure 4 shows examples of a broadband polarizer with Rp < 0.2 % for AOI = 55° within a bandwidth of 25 nm in the wavelength range of Yb-doped fiber lasers (figure 4a) and a narrowband polarizer which is optimized for very low
Rp values at a single wavelength (figure 4b). Figure 4c shows a comparison of the calculated transmittance spectrum for p-polarized lightand a measurement in a CRD set-up. Figure 4d shows Tp vs. AOI for the same polarizer (measured at 1042 nm). These measurements provethat Tp > 99.9 % can be achieved by angle adjustment. This is important especially for intra cavity applications.
Rs
100
90
80
70
60
50
40
30
20
10
0
1000

Rp

Rp (0 – 1 %)AOI = 55°

b

R [%]

R [%]

a

1010

1020

1030

1040

1050

1060

1070

1080

Rs
100
90
80
70
60
50
40
30
20
10
0
1000

1010

1020

wavelength [nm]c

Measurement

Tp (theory)1040

Rp (0 – 1 %)1050

AOI = 55°

1060

1070

1080

Tp

λ = 1042nm

wavelength [nm]Tp (CRD-measurement) AOI = 55°dMeasurement

100.0
99.8
T [%]

T [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

1030

Rp

99.6
99.4
99.2

1020

1030

1040

1050

1060

wavelength [nm]

99.0

50

52

54

56

58

60

AOI [deg]

Figure 4: Reflectance and transmittance spectra of thin film polarizers (TFPs)a) Reflectance spectra for s- and p-polarized light of a broadband thin film polarizer showing a bandwidth of 25 nm with Rp < 0.2 % (AOI = 55°)b) Reflectance spectra for s- and p-polarized light of a narrowband thin film polarizer which is optimized for very low Rp values and easy angle
adjustment for the optimization of the polarizer performance (AOI = 55°)c) Calculated and measured transmittance spectra for p-polarized light of the narrowband thin film polarizer shown in figure 4b (AOI = 55°).
Tp > 99.8 % is reached with a bandwidth of 15 nm and Tp > 99.9 % can be achieved within a bandwidth of 5 nm. The spectral position of thistransmittance maximum can be adjusted to any wavelength between 1035 nm and 1045 nm by angle adjustment.
d) Transmittance spectrum Tp vs. AOI at 1042 nm measured at the polarizer shown in figure 4c

Picosecond Lasers based on Yb-doped Materials
Picosecond laser optics require specially designed coatings to achieve high laser damage thresholds. For detailed information please see
page 54 ff. For GTI mirrors which are often used for pulse compression from the ps range down to a few hundred fs please see page64 ff.

19

Selection of Optical Components for Common Laser Types
High Power Lasers on the Basis of Yb- and Nd-doped Materials (1020 – 1080 nm)

Alignment and Process Monitoring
Ru
100
90
80
70
60
50
40
30
20
10
0
500

AOI = 45°

b

R [%]

R [%]

a

750

1000

1250

1500

1750

2000

2250

2500

Ru
100
90
80
70
60
50
40
30
20
10
0
350

550

750

wavelength [nm]

950

1150

AOI = 45°

1350

1550

Rp

Ru

wavelength [nm]Figure 5: Reflectance spectra of turning mirrors with special features for alignment and process monitoringa) Turning mirror with low IR reflectance, i.e. high IR transmittance for process monitoringb) Silver based turning mirror with Ru (45°, 1064 nm) > 99.8 % and with Ru > 80 % for an alignment laser in the red spectral range

Beam Splitters and Output Couplers
75 %

98 %
100
90
80
70
60
50
40
30
20
10
0

50 %

60 %

30 %

AOI = 0°

b

R [%]

R [%]

a

950

1000

1050

1100

1150

1200

Rs
100
90
80
70
60
50
40
30
20
10
0

950

1000

wavelength [nm]

1050

1100

1150

wavelength [nm]Figure 6: Reflectance spectra of output couplers and beam splitters (center wavelength 1064 nm)a) Output couplers with different degrees of reflectanceb) Common 50:50 beam splitter for unpolarized light• Beam splitters and output couplers can be produced with a
precisely adjusted degree of reflectance:• Common types:
Rs,p > 95 % ± 0.5 %Rs,p = 80 % … 95 % ± 1 %Rs,p = 10 % … 80 % ± 2 %Non Polarizing Beam Splitters
Rs = 66 %Rp = 66 %

100
90
80
70
60
50
40
30
20
10
0

Rs = 50 %Rp = 50 %Rs = 33 %Rp = 33 %AOI = 45°

b

R [%]

R [%]

a

1030

1040

1050

1060

1070

1080

1090

1100

Measurement
100
90
80
70
60
50
40
30
20
10
0
1030
1040

wavelength [nm]

Rs

1050

1060

1070

Rp

1080

AOI = 45°1090

wavelength [nm]Figure 7: Non-polarizing beam splittersa) Calculated reflectance spectra of 3 types of non-polarizing beam splitters for AOI = 45°b) Measured reflectance spectra of the 50 % beam splitter• Beam splitters with Rs ≈ Rp (|Rs – Rp| < 1.5 %) for AOI = 45°
and different degrees of reflectance:• Common types:
Rs,p = 66 % ± 1 %Rs,p = 50 % ± 2 %Rs,p = 33 % ± 3 %20• All non-polarizing beam splitters with rear side AR:
Rs ≈ Rp ≤ 0.6 %1100

Selection of Optical Components for Common Laser Types
Second Harmonic of High Power Lasers on the Basis of Yb- and Nd-doped Materials (515 nm, 532 nm)Second Harmonic of High Power Lasers on the Basis of
Yb- and Nd-doped Materials (515 nm, 532 nm)
The harmonics of Yb- and Nd-based high power lasers are widely used material processing as well as for measurement applications.
Moreover, the second harmonic of these lasers is often used as a pump source for Ti:Sapphire lasers. LAYERTEC offers a variety of optics
for 532 nm: dual wavelength mirrors, separators, thin film polarizers and non-polarizing beam splitters, but also cavity optics for compact
diode pumped lasers of different configurations. Coatings for 515 nm are available as well. All designs are calculated according to customer
specifications.

Dual Wavelength Turning Mirror
Rs

Rp

900

1000

AOI = 45°

100.0

R [%]

99.8
99.6
99.4
99.2
99.0
400

500

600

700

800

1100

1200

wavelength [nm]Figure 1: Reflectance spectra of a dual wavelength turning mirror
HRs,p (45°, 532 + 1064 nm) > 99.9 %

100
90
80
70
60
50
40
30
20
10
0

R (99 – 100 %) AOI = 0°

R

R [%]

R [%]

Dual Wavelength Cavity Mirror

400

500

600

700

800

900

1000

1100

1200

R

100
90
80
70
60
50
40
30
20
10
0
450

550

650

wavelength [nm]750

R (99 – 100 %)

850

950

1050

AOI = 0°

1150

1250

wavelength [nm]Figure 2: Reflectance spectra of a dual wavelength cavity mirror with hightransmittance for the pump wavelength (808 nm)

Figure 3: Reflectance spectra of an HR mirror for 1064 nm with additional
output coupler for 532 nm:
HR (0°, 1064 nm) > 99.9 % + R (0°, 532 nm ) = 99 % ± 0.3 %Separators for the Second Harmonic and the Fundamental Wave
R
100
90
80
70
60
50
40
30
20
10
0

R (99 – 100 %)AOI = 0°

b

R [%]

R [%]

a

400

500

600

700

800

900

1000

1100

1200 1300

Rs
100
90
80
70
60
50
40
30
20
10
0

500

wavelength [nm]Rs (99 – 100 %)

Rp

600

800

700

Rp (99 – 100 %) AOI = 45°

900

1000

1100

wavelength [nm]Figure 4: Reflectance spectra of separators for the second harmonic and the fundamental wavelength:a) HR (0°,1064 nm) > 99.9 % + R (0°, 532 + 808 nm) < 3 %b) HRs,p (45°, 515 + 532 nm) > 99.8 % + Rs (45°, 1030 + 1064 nm) < 5 % + Rp (45°, 1030 + 1064 nm) < 2 %Separators with different features are available according to customer specifications.
21Selection of Optical Components for Common Laser Types
Second Harmonic of High Power Lasers on the Basis of Yb- and Nd-doped Materials (515 nm, 532 nm)

Thin Film Polarizers

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0

500

510

520

530

Rp

540

AOI = 55°

550

560

wavelength [nm]Figure 5: Reflectance spectra of a thin film polarizer for 532 nm

The transmittance of thin film polarizers for p-polarized light can be measured in-house with high accuracy using a modified Cavity RingDown set-up.

Non-Polarizing Beam Splitters

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0
480

490

500

510

520

530

540

550

Rp

AOI = 45°

560

570

580

wavelength [nm]Figure 6: Reflectance spectra of a non-polarizing beam splitter for 532 nmwith Rs = Rp = 50 ± 2 % (|Rs – Rp| < 3 %)Coating on Nonlinear Optical Crystals
AOI = 0°AOI = 0°

10

6

R [%]

R [%]

8

4
2
0
450

550

650

750

850

950

1050

1150

wavelength [nm]Figure 7: Reflectance spectrum of a dual wavelength antireflection coatingon KTP for 532 nm and 1064 nm

100
90
80
70
60
50
40
30
20
10
0

450

550

650

750

850

950

1050

1150

wavelength [nm]Figure 8: Reflectance spectrum of a dichroic mirror on KTP:
HR (0°, 532 nm) > 99.98 % + R (0°, 1064 nm) < 0.2 % optimized
for very high transmittance at 1064 nm

Nonlinear optical crystals are the key elements for frequency conversion. LAYERTEC offers a variety of coatings on crystals like KTP andlithium niobate. For more information about coatings on crystals see page 84 f.

22

Selection of Optical Components for Common Laser Types
Third Harmonic of High Power Lasers on the Basis of Yb- and Nd-doped Materials (343 nm, 355 nm)

Third Harmonic of High Power Lasers on the Basis of
Yb- and Nd-doped Materials (343 nm, 355 nm)
Standard Components
The third harmonic of Nd:YAG, Nd:YVO4 and Yb:YAG lasers has gained importance in the field of material processing, for measurement
applications and as pump source for optical parametric oscillators. LAYERTEC manufactures a wide range of optics for 355 nm: single andmultiple wavelength mirrors, separators, thin film polarizers and antireflection coatings. The coating designs shown here are calculated for
355 nm, but designs for 343 nm are available as well. In general, the coating designs are optimized according to customer specifications.

R [%]Turning Mirrors
100
90
80
70
60
50
40
30
20
10
0

Rs

250

270

Rs (90 – 100 %)

290

310

330

Rp

350

Rp (90 – 100 %)

370

390

410

AOI = 45°

430

450

wavelength [nm]Figure 1: Reflectance spectra of a turning mirror:
HRs (45°, 355 nm) > 99.9 % + HRp (45°, 355 nm) > 99.5 %Standard Separators

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0

300

400

500

600

700

800

Rp

900

AOI = 45°

1000

1100

wavelength [nm]Figure 2: Reflectance spectra of a standard separator reflecting the third harmonic and transmitting the second harmonic and the fundamental wave:
HRs (45°, 355 nm) > 99.9 % + HRp (45°, 355 nm) > 99.5 %+ Rp (45°, 532 + 1064 nm) < 2 %+ Rs (45°, 532 nm) < 5 % + Rs (45°, 1064 nm) < 10 %Special Separators

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0
300

400

500

600

700

800

Rp

900

AOI = 45°

1000

1100

wavelength [nm]Figure 3: Reflectance spectra of a special separator optimized for low reflectance at 1064 nm:
HRs (45°, 355 nm) > 99.9 % + HRp (45°, 355 nm) > 99.5 %+ Rp (45°, 532 + 1064 nm) < 2 % + Rs (45°, 532 nm) < 5 %+ Rs (45°, 1064 nm) < 2 %23

Selection of Optical Components for Common Laser Types
Third Harmonic of High Power Lasers on the Basis of Yb- and Nd-doped Materials (343 nm, 355 nm)

Windows and Lenses
0°30° Rs30° RpAOI = 0°

5.0

3.0

R [%]

R [%]

4.0

2.0
1.0
0

300

320

340

360

380

400

420

5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0

300

400

500

600

wavelength [nm]

700

800

900

1000

1100 1200

wavelength [nm]Figure 4: Reflectance spectra of a single wavelength AR coating for355 nm optimized for AOI = 0°– 30°

Figure 5: Reflectance spectrum of a triple wavelength antireflection coating on Fused Silica for 355 nm, 532 nm and 1064 nm

Sputtered Multiple Wavelength Mirrors
Rp

Rs

AOI = 45°

R [%]

R [%]

Rs
100
99
98
97
96
95
94
93
92
91
90
300

400

500

600

700

800

900

1000 1100 1200 1300

100
99
98
97
96
95
94
93
92
91
90

300

330

360

390

420

450

480

Rp

510

540

AOI = 45°

570

600

wavelength [nm]wavelength [nm]Figure 6: Reflectance spectra of a triple wavelength turning mirror for
355 nm, 532 nm and 1064 nm

Figure 7: Reflectance spectra of a dual wavelength turning mirror for
355 nm and 532 nm

Sputtered Thin Film Polarizers
Rs
100
90
80
70
60
50
40
30
20
10
0

320

340

Rp

AOI = 55°

360

The transmittance of p-polarized light can be optimized by angle
adjustment. Tilting the polarizer by ± 2° shifts the minimum of Rp
to longer or shorter wavelengths which can improve the polarization ratio significantly.

380

wavelength [nm]Figure 8: Reflectance spectra of a thin film polarizer for 355 nm:
HRs (55°, 355 nm) > 99.5 % + Rp (55°, 355 nm) < 2 %Table 1: Technical Data of Mirrors and Separators

Type of Coating

IAD

IBS

Mirror for AOI = 0°

R > 99.9 %R > 99.9 %Turning Mirror

Rs > 99.9 %,Rp > 99 %Rs > 99.95 %,Rp > 99.8 %Rs (355 nm) > 99.9 %Rs (355 nm) > 99.9 %Rp (355 nm) > 99 %Rp (355 nm) > 99.7 %Rs (532 nm) < 5 %Rs (532 nm) < 2 %Rp (532 nm) < 2 %Rp (532 nm) < 1 %Rs (1064 nm) < 10 %Rs (1064 nm) < 2 %Rp (1064 nm) < 2 %Rp (1064 nm) < 1 %Separator AOI = 45°24

Selection of Optical Components for Common Laser Types
Higher Harmonics of High Power Lasers on the Basis of Yb- and Nd-doped Materials (213 nm, 266 nm)

Higher Harmonics of High Power Lasers on the Basis of
Yb- and Nd-doped Materials (213 nm, 266 nm)
The harmonics of Nd:YAG and Nd:YVO4 lasers are widely used for material processing as well as for measurement applications.
LAYERTEC offers a variety of optics utilizing the fourth (266 nm) and fifth (213 nm) harmonic. All designs are calculated according tocustomer specifications.

Multiple Wavelength Mirrors
Rp

AOI = 45°

Rs

R [%]

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0

240

260

280

300

320

340

360

380

400

100
90
80
70
60
50
40
30
20
10
0

200

400

600

Rs (99 – 100 %)800

AOI = 45°

1000

1200

wavelength [nm]wavelength [nm]Figure 1: Reflectance spectra of a dual wavelength turning mirror for
266 nm and 355 nm

Figure 2: Reflectance spectra of a four wavelength turning mirror:
HRs (45°, 266 nm + 355 nm) > 99 %+ HRs (45°, 532 nm + 1064 nm) > 99.9 %R [%]Separators for the Fourth Harmonic

100
90
80
70
60
50
40
30
20
10
0

240

340

440

540

640

Rs

Rp

AOI = 45°

840

940

1040 1140

740

wavelength [nm]Figure 3: Reflectance spectra of a separator reflecting the fourth harmonic
and transmitting the lower harmonics and the fundamental
wave

Separators for the Fifth Harmonica

Measurement

Ru

Rs

Rp

AOI = 45°

100

b

R [%]

R [%]

95
90
85
80

190

195

200

205

210

215

220

225

230

Rs
100
90
80
70
60
50
40
30
20
10
0
180

280

380

480

wavelength [nm]

580

680

780

Rp

AOI = 45°

880

980

1080

wavelength [nm]Figure 4: Reflectance spectra of fluoride coatings on CaF2:a) Turning mirror for the fifth harmonic (measured spectra)b) Separator reflecting the fifth harmonic and transmitting the lower harmonics and the fundamental

25

Selection of Optical Components for Common Laser Types
Higher Harmonics of High Power Lasers on the Basis of Yb- and Nd-doped Materials (213 nm, 266 nm)

Special Separators
The fifth harmonic at 213 nm is a critical wavelength for oxide coatings because the absorption edge of aluminum oxide begins in thiswavelength range. However, aluminum oxide is the only high index oxide material which can be used for 213 nm. Compared to fluorides,
oxide coatings are hard and show low scattering losses. Fluorides in contrast exhibit higher LIDT values and extended lifetime for medium
and high power applications.
Ru
100
90
80
70
60
50
40
30
20
10
0
200

Tu

AOI = 45°b

R, T [%]

R, T [%]

a

210

220

230

240

250

260

270

280

290

300

Ru
100
90
80
70
60
50
40
30
20
10
0
200

210

220

230

240

wavelength [nm]

250

260

270

Tu

AOI = 45°

280

290

wavelength [nm]Figure 5: Reflectance spectra of separators for the fourth and fifth harmonics:
HRu (45°, 266 nm) > 98 % + Ru (45°, 213 nm) < 10 % for unpolarized lighta) Oxide coating optimized for low scattering lossesb) Fluoride coating for high laser-induced damage thresholds

Thin Film Polarizers
Sputtering techniques enable LAYERTEC to offer thin film polarizers also for the fourth harmonic of the Nd:YAG laser.

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0

240

250

260

Rp

AOI = 56°

270

280

wavelength [nm]Figure 6: Reflectance spectrum of a thin film polarizer for 266 nm:
HRs (56°, 266 nm) > 98 % + Rp (56°, 266 nm) < 5 %,Tp (56°, 266 nm) ≈ 95 %Table 1: Common specifications of separators for the harmonics in the UV

Separator
Type

Technology

Reflectance atCenter Wavelength

Reflectance at the Corresponding Longer Nd:YAG Wavelengths
266 nm

Rs

Rp

Rs

Rp

Rs

Rp

> 99.9 %> 99.5 %<5%<2%< 10 %<2%

Sputtered> 99.9 %> 99.8 %

<2%

<1%

<2%

<1%

4th harmonic,
266 nm

IAD> 99.7 %> 99.4 %<5%<2%< 10 %<2%< 10 %<2%

Sputtered> 99.8 %> 99.5 %

<5%

<1%

<2%

<1%

<2%

<1%

Evaporated> 97 %> 93 %< 10 %<2%< 10 %<2%< 10 %<2%*

26

Fluoride coating on CaF2

<5%

<2%

Rs

Rp

1064 nm

IAD

5 harmonic,
213 nm*Rp

532 nm

3rd harmonic,
355 nmthRs

355 nm300

Selection of Optical Components for Common Laser Types
Weak Nd:YAG or Nd:YVO4 Laser Lines (915 nm, 946 nm, 1123 nm, 1340 nm)

Weak Nd:YAG or Nd:YVO4 Laser Lines(915 nm, 946 nm, 1123 nm, 1340 nm)
Neodymium doped crystals exhibit laser transitions at different wavelengths. Table 1 and table 2 give an overview about the laser wavelengths of the most common Nd-doped materials Nd:YAG and Nd:YVO4.
Table 1: Laser lines and corresponding wavelengths of thesecond harmonic of Nd:YAG

Table 2: Laser lines and corresponding wavelengths of thesecond harmonic of Nd:YVO4

Laser Lines

Second Harmonic

Laser Lines

Second Harmonic

946 nm473 nm915 nm

457 nm1064 nm

532 nm1064 nm

532 nm1123 nm

561 nm1342 nm

671 nm1319 nm

659 nm1338 nm

669 nm1415 nm

708 nm1444 nm

722 nm

A variety of laser lines in the VIS and NIR can be obtained from these crystals. This process is utilized to build compact diode pumped solidstate lasers with a variety of wavelengths which are used for measurement applications as well as for projection systems (RGB lasers).
The strongest laser transition in both materials is the 1064 nm line. Efficient laser radiation at other wavelengths is only possible by suppressing this line. LAYERTEC offers a variety of laser mirrors for this application.
Compact laser designs also include the pump diode (808 nm) and a unit for the second harmonic generation. This is the reason why
coatings for Nd:YAG or Nd:YVO4 wavelengths apart from 1064 nm mostly show several spectral regions of high transmittance as well as
high reflectance. All coatings are designed according to customer specifications, because the specifications depend on the laser design. All
examples on these pages are for Nd:YAG wavelengths. Coatings for Nd:YVO4 can be designed and produced as well.

R [%]AOI = 0°
100
90
80
70
60
50
40
30
20
10
0
400

500

600

700

800

900

Table 3: Special features of the mirror from figure 1

FeatureReflectance

Suppression of the strongest laser line

R (0°, 1064 nm) < 5 %HR mirror for the weak laser line

R (0°, 946 nm) > 99.95 %High transmittance for thepump wavelength

R (0°, 808 nm) < 2 %HR mirror for the second harmonicof the weak laser line

HR (0°, 473 nm) > 99.85 %1000 1100 1200 1300 1400

wavelength [nm]Figure 1: Reflectance spectrum of a dual wavelength mirror for a weaklaser line and its second harmonic with high transmittance forthe pump wavelength and the strongest laser line:
HR (0°, 473 nm) > 99.85 % + HR (0°, 946 nm) > 99.95 %+ R (0°, 808 nm) < 2 % + R (0°, 1064 nm) < 5 %

R [%]

R
100
90
80
70
60
50
40
30
20
10
0

450

550

650

750

850

950

R (99 – 100 %)AOI = 0°

Table 4: Special features of the mirror from figure 2

FeatureReflectance

HR mirror for the weak laser line

HR (0°, 1123 nm) > 99.9 %Suppression of the strongest laser line

R (0°, 1064 nm) < 50 %High transmittance for thepump wavelength

R (0°, 808 nm) < 10 %High transmittance for the second
harmonic of the weak laser line

R (0°, 561 nm) < 2 %1050 1150 1250 1350 1450

wavelength [nm]Figure 2: Reflectance spectrum of a dichroic mirror with high transmittance for the pump wavelength which also suppresses the1064 nm line:
HR (0°, 1123 nm) > 99.9 % + R (0°, 561 nm) < 2 %+ R (0°, 808 nm) < 10 % + R (0°, 1064 nm) < 50 %27

Selection of Optical Components for Common Laser Types
Weak Nd:YAG or Nd:YVO4 Laser Lines (915 nm, 946 nm, 1123 nm, 1340 nm)

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0

500

600

700

800

900

Rp

1000

AOI = 56°

1100

1200

wavelength [nm]Table 5: Special features of the mirror from figure 3

FeatureReflectance

HR for s-polarized light of the weaklaser line

HRs (56°, 1123 nm) > 99.9 %Suppression of p-polarized light of the
weak laser line

Rp (56°, 1123 nm) < 50 %Suppression of the strongest laser line

Rs,p (56°,1064 nm) < 50 %High transmittance for the pumpwavelength

Rs,p (56°, 808 nm) < 10 %High transmittance for the second
harmonic of the weak laser line

Rs,p (56°, 561 nm) < 10 %Figure 3: Reflectance spectra of a thin film polarizer with high transmittance for the pump wavelength and the second harmonic which
also suppresses the 1064 nm line:
HRs (56°, 1123 nm) > 99.9 % + Rp (56°, 1123 nm) < 50 %+ Rs,p (56°, 561 nm + 808 nm) < 10 %+ Rs,p (56°, 1064 nm) < 50 %

R [%]

R
100
90
80
70
60
50
40
30
20
10
0

R (99 – 100 %)AOI = 0°FeatureReflectanceBroadband HR
mirror for several
laser lines

HR (0°, 1064 nm + 1123 nm + 1319 nm) > 99.9 %High transmittancefor the second
R (0°, 532 – 561 nm + 659 nm) < 2 %harmonics of theselaser lines
500

600

700

800

900

1000

1100

1200

1300

1400

wavelength [nm]Figure 4: Reflectance spectrum of a dichroic mirror with high reflectancefor the NIR wavelengths and high transmittance for the corresponding second harmonic wavelengths:
HR (0°, 1064 nm + 1123 nm + 1319 nm) > 99.9 %+ R (0°, 532 – 561 nm + 659 nm) < 2 %28

Table 6: Special features of the mirror from figure 4

Selection of Optical Components for Common Laser Types
Ho:YAG and Tm:YAG Lasers (2010 nm, 2100 nm)

Ho:YAG and Tm:YAG Lasers (2010 nm, 2100 nm)
Ho:YAG and Tm:YAG lasers emitting at wavelengths of 2010 nm and 2100 nm are widely used for medical applications. LAYERTEC offers
optical coatings for this wavelength range with high laser-induced damage thresholds and long lifetimes.

Cavity Mirrorsa

AOI = 0°

b

R [%]

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1800

1900

2000

2100

2200

2300

2400

R
100
90
80
70
60
50
40
30
20
10
0

700

1000

1300

wavelength [nm]1600

R (99 – 100 %)1900

AOI = 0°

2200

2500

wavelength [nm]Figure 1: Reflectance spectra of cavity mirrors:a) HR cavity mirrorb) Pump mirror with high transmittance around 808 nm• HR cavity and pump mirrors with R > 99.9 %• High laser-induced damage thresholds

Turning Mirrors
a

Rs

Rp

AOI = 45°

b
100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1800

Rs

Rp

AOI = 45°

R [%]

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1700

1800

1900

2000

2100

wavelength [nm]

2200

2300

1900

2000

2100

2200

2300

2400

wavelength [nm]Figure 2: Reflectance spectra of turning mirrors for:a) 2010 nmb) 2100 nm

The coating materials are chosen to guarantee high laser-induced damage thresholds. To achieve the maximum reflectance for p-polarization, mirrors should be specified for either 2010 nm or 2100 nm.
• Turning mirrors with R > 99.9 % for s-polarized light and R > 99.8 % for p-polarized light at AOI = 45°• High laser-induced damage thresholds

29Selection of Optical Components for Common Laser Types
Ho:YAG and Tm:YAG Lasers (2010 nm, 2100 nm)

Output Couplers
AOI = 0°
100

R [%]

90

Output couplers with precisely adjusted degrees of reflectance:• R > 95 % ± 0.5 %• R = 80 … 95 % ± 1 %• R = 10 … 80 % ± 2 %

80
70
60
50
1800

1900

2000

2100

2200

2300

2400

2500

wavelength [nm]Figure 3: Reflectance spectrum of an output coupler with
R = 82 % ± 1 % at 2100 nm

Edge Filters
R (99 – 100 %)AOI = 0°

R [%]

R [%]

R
100
90
80
70
60
50
40
30
20
10
0
1600

1700

1800

1900

2000

2100

2200

wavelength [nm]R
R (99 – 100 %)AOI = 0°
100
90
80
70
60
50
40
30
20
10
0
1900 1930 1960 1990 2020 2050 2080 2110 2140 2170 2200
wavelength [nm]Figure 4: Reflectance spectra of a cavity mirror for 2010 nm suppressing
the 2100 nm line

Figure 5: Reflectance spectra of a steep edge filter for the separation of
the 2010 nm and 2100 nm lines

Thin Film Polarizers

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0
1900

Rs (99 – 100 %)Rp

AOI = 55°

• Thin film polarizers designed at Brewster’s angle (≈ 55°)
exhibit a higher Tp/Ts ratio and a considerably broader bandwidth than those at AOI = 45°

1950

2000

2050

2100

2150

wavelength [nm]Figure 6: Reflectance spectra of a thin film polarizer for 2010 nm with
Rs > 99.8 %, Rp < 2 %, AOI = 55°

30• Separation of the s- and p-polarized component of the light(s-polarized light is reflected, p-polarized light is transmitted)

Selection of Optical Components for Common Laser Types
Ho:YAG and Tm:YAG Lasers (2010 nm, 2100 nm)

Windows and Lenses
Lens materials according to customer specifications:• Fused Silica with low OH-content, like Suprasil® 3001/3002/300• Infrasil®, sapphire and undoped YAG can be used
• Special AR coatings for high index materials such as GGG on requesta

AOI = 0°

b

2.00
1.75
1.25

R [%]

R [%]

1.50
1.00
0.75
0.50
0.25
0.00
1850

1900

1950

2000

2050

2100

2150

wavelength [nm]

1800

1900

2000

2100

2200

2300

2400

wavelength [nm]

c

R [%]

AOI = 0°
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0

AOI = 0°
10
9
8
7
6
5
4
3
2
1
0
600

800

1000

1200

1400

1600

wavelength [nm]

1800

2000

2200 2400

Figure 7: Reflectance spectra of typical antireflection coatings:a) Single wavelength AR coating for 2010 nmb) Broadband AR coating 2010 – 2100 nmc) Dual wavelength AR coating for the pump and laser wavelength (808 nm + 2010 nm)

31

Selection of Optical Components for Common Laser Types
Er:YAG Lasers and the 3 µm Region

Er:YAG Lasers and the 3 µm Region
Er:YAG lasers are widely used in medical applications, especially in dermatology, due to the high absorption coefficient of water for
2940 nm radiation. This makes surgical applications easier but is also a challenge for the optical coatings which must be completely free ofwater. Coatings produced by magnetron sputtering have proved to be ideal for this kind of application.

Cavity Mirrors

R [%]AOI = 0°
100
90
80
70
60
50
40
30
20
10
0

2000

2250

2500

2750

3000

3250

3500

wavelength [nm]Figure 1: Reflectance spectrum of an HR cavity mirror
HR (0°, 2940 nm) > 99.8 %Pump Mirrors

R [%]AOI = 0°
100
90
80
70
60
50
40
30
20
10
0

• Reflectance of cavity mirrors and pump mirrors: R > 99.9 % at
AOI = 0°• Pump mirrors with high transmittance between 800 nm and1100 nm for pumping with a Nd:YAG laser or a diode laser

800

1300

1800

2300

2800

3300

wavelength [nm]Figure 2: Reflectance spectrum of a HR cavity mirror with an HT region
between 800 nm and 1100 nm

Turning Mirrors

R [%]

Ru
100
90
80
70
60
50
40
30
20
10
0

2000

2250

2500

2750

3000

AOI = 45°

3250

3500

wavelength [nm]Figure 3: Reflectance spectrum of a turning mirror for unpolarized light

LIDT Info
400 J/cm², 2940 nm, 400 µs

32• Reflectance of turning mirrors: R > 99.8 % at AOI = 45° for
unpolarized lightSelection of Optical Components for Common Laser Types
Er:YAG Lasers and the 3 µm Region

Beam Combiners and Alignment Laser Mirrors
Ru
100
90
80
70
60
50
40
30
20
10
0
500

AOI = 45°

b

R [%]

R [%]

a

1000

1500

2000

2500

3000

3500

Ru
100
90
80
70
60
50
40
30
20
10
0

500

1000

1500

wavelength [nm]

2000

2500

AOI = 45°

3000

3500

wavelength [nm]Figure 4: Reflectance spectra of turning mirrorsa) Dual wavelength turning mirror for 2940 nm and an alignment laser between 630 nm and 655 nmb) Separator/combiner for 2940 nm and an alignment laser between 630 nm and 655 nm• Designs for beam splitters and alignment laser mirrors are calculated according to customer specifications

Output Couplers and Lenses
R = 84 % ±1 %100

R = 70 % ±1 %AOI = 0°• AR coatings with residual reflectance of R < 0.2 % on the rearside of output couplers as well as on lenses and windows

90
R [%]

• Output couplers with precisely adjusted degrees of reflectance(tolerances of ± 1 % at reflectance values between 70 % and
90 %)

80

• Infrasil®, sapphire and undoped YAG can be used (for substrate materials see page 138 ff.)

70
60
50
2800

2850

2900

2950

3000

3050

3100

wavelength [nm]Figure 5: Reflectance spectra of output couplers with
R = 70 % ± 1 % and R = 84 % ± 1 %33

Ultrafast Laser Optics

Ultrafast Laser Optics

Chapter Index
Introduction to Ultrafast Laser Optics...............................35
GDD and TOD........................................................................36
Standard Ultrafast Laser Optics(120 – 150 nm Bandwidth)................................................37
Cavity Mirrors AOI = 0°..........................................................37
Pump Mirrors AOI = 0°...........................................................37
Turning Mirrors AOI = 45°......................................................38
Output Couplers AOI = 0°......................................................38
Beam Splitters for p-polarized light at AOI = 45°....................38
Beam Splitters for s-polarized light at AOI = 45°.....................39
Negative Dispersion Mirrors AOI = 0°.....................................39
High Dispersion Mirrors AOI = 0°............................................40
High Dispersion Mirror Pairs AOI = 0°.....................................40
Thin Film Polarizers for AOI = 55°...........................................41
Thin Film Polarizers for AOI = 65°...........................................41
Thin Film Polarizers for AOI = 80°...........................................42
Non-polarizing Beam Splitters for AOI = 45°...........................42
Antireflection Coatings...........................................................43
Broadband Ultrafast Laser Optics(200 – 300 nm Bandwidth)................................................44
Mirror Pairs for AOI = 0°.........................................................44
Turning Mirrors for s-polarized Light at AOI = 45°..................44
Turning Mirrors for p-polarized Light at AOI = 45°..................45
Output Couplers for AOI = 0°.................................................45
Beam Splitters for p-polarized Light at AOI = 45°....................45
Beam Splitters for s-polarized Light at AOI = 45°....................46
Negative Dispersion Pump Mirror Pairs for AOI = 0°...............46
Thin Film Polarizers for AOI = 70°...........................................47
High Negative Dispersion Mirror Pairs for AOI = 0°.................47
Mirror Pairs with Optimized Third Order Dispersion
for AOI = 0°...........................................................................48
Octave Spanning Ultrafast Laser Optics(400 – 500 nm Bandwidth)................................................49
Negative Dispersion Laser Mirror Pairs for AOI = 0°................49
Negative Dispersion Pump Mirror Pairs for AOI = 0°...............49
Negative Dispersion Turning Mirror Pairs forp-polarized Light for AOI = 0°................................................50
Output Couplers for AOI = 0°.................................................50
Beam Splitters for p-polarized Light at AOI = 45°....................51
Beam Splitters for s-polarized Light at AOI = 45°....................51
Silver Mirrors for Ultrafast Lasers (550 – 1100 nm)...........52
Silver Mirrors Optimized for Laser Applications.......................52
Silver Mirrors with Enhanced Reflectance...............................5334

High Power Ultrafast Laser Optics (550 – 1100 nm)..........54
Overview about Laser-Induced Damage Thresholds of
Ultrafast Laser Optics.............................................................55
Metallic High Power Mirrors...................................................56
GDD of High Power Ultrafast Laser Mirrors.............................56
Components for the Second Harmonic of theTi:Sapphire Laser (300 – 600 nm)......................................57
Dual Wavelength Mirrors for AOI = 0°....................................57
Dual Wavelength Turning Mirrors for AOI = 45°.....................58
Separators for the Second Harmonic from theFundamental for AOI = 45°....................................................58
Negative Dispersion Mirror Pair for the 400 nm
Spectral Range at AOI = 0°.....................................................59
Components for the Third Harmonic of theTi:Sapphire Laser (250 – 400 nm)......................................60
Dual Wavelength Turning Mirrors for AOI = 45°.....................60
Triple Wavelength Turning Mirrors for AOI = 45°....................60
Separators for the Third Harmonic from the Second
Harmonic and the Fundamental Wave for AOI = 45°..............60
Negative Dispersion Mirror Pair for AOI = 0°...........................61
Components for the Higher Harmonics of theTi:Sapphire Laser (140 – 250 nm)......................................62
Turning Mirrors and Separators for the Fourth Harmonicat AOI = 45°...........................................................................62
Components for the Fifth Harmonic at AOI = 45°...................62
Components for the Sixth Harmonic at AOI = 45°..................63
Bandwidth of the Reflectance and Low-GDD Rangeof Standard Components.......................................................63
Gires-Tournois-Interferometer (GTI) Mirrors(600 – 1600 nm)................................................................64
GTI-Mirrors for Yb:YAG and Yb:KGW-Lasers...........................64
Optical Losses of GTI-Mirrors..................................................65
Coating Homogenity and Reproducibility of GTI-Mirrors.........66
Optics for Ultrafast Lasers
in the Wavelength Range of 1000 – 1600 nm...................67
Negative Dispersion Laser and Pump Mirrors for AOI = 0°......67
GTI-Mirrors for AOI = 0°.........................................................68
Broadband Negative Dispersion Mirror Pairs for AOI = 0°.......68
Broadband Negative Dispersion Turning Mirrors
for AOI = 45°.........................................................................69

Ultrafast Laser Optics
Introduction to Ultrafast Laser Optics

Introduction to Ultrafast Laser Optics
Ultrafast lasers are used in numerous applications such as time resolved spectroscopy, precision material processing and non-linear optics.
Driven by these applications, recent developments in this field are directed to lasers generating higher output power and shorter pulses.
Currently, most short pulse physics is done with Ti:Sapphire lasers. Solid-state lasers based on other transition metal or rare earth metal
doped crystals (Nd:YAG, Nd:YVO4, Yb:KGW) are also used for the generation of ultrashort pulses. The reproducible generation of sub-100
fs-pulses is closely connected to the development of broadband low loss dispersive delay lines consisting of prism or grating pairs or ofdispersive multilayer reflectors.
The spectral bandwidth of a pulse is related to the pulse duration by a well-known theorem of Fourier analysis. For instance, the bandwidth (FWHM) of a 100 fs Gaussian pulse at 800 nm is 11 nm. For shorter pulses, the wavelength spectrum becomes significantly broader.
A 10 fs pulse has a bandwidth of 107 nm.

optical medium

pulse

stretching of temporal envelope

Figure 1: Broadening of a pulse by propagation through an optical medium (schematic drawing)If such a broad pulse passes through an optical medium, the spectral components of this pulse propagate with different speeds. Dispersive media, like glass, impose a so-called “positive chirp” on thepulse, meaning that the short wavelength (“blue”) components aredelayed with respect to the long wavelength (“red”) components(see schematic drawing in figure 1).
A similar broadening can be observed if a pulse is reflected by adielectric mirror and the bandwidth of the pulse is larger or equal
to the width of the reflection band of the mirror. Consequently,
broadband mirrors consisting of a double stack system cause pulse
broadening because the path lengths of the spectral componentsof the pulse are extremely different in these coatings.

In the sub-100 fs-regime it is essential to control the phase properties of each optical element over the extremely wide bandwidth of the
fs-laser. This holds not only for the stretcher and compressor units, but also for the cavity mirrors, output couplers and the beam propagation system. In addition to the power spectrum, i.e. reflectance or transmittance, the phase relationship among the Fourier components ofthe pulse must be preserved in order to avoid broadening or distortion of the pulse.
Mathematical analysis of the phase shift, which is applied to a pulse passing through a medium or being reflected by a mirror (see part
GDD and TOD), shows that the main physical properties which describe this phenomenon are the group delay dispersion (GDD) and thethird order dispersion (TOD). These properties are defined as the second and third derivative of the phase with respect to the frequency.
Especially designed dielectric mirrors offer the possibility to impose
a “negative chirp” on a pulse. Thus, the positive chirp which resultsfrom crystals, windows, etc. can be compensated. The schematic
drawing in figure 2 explains this effect in terms of different optical
path lengths of blue, green and red light in a negative dispersion
mirror.

Figure 2: Optical path lengths of blue, green and red light in a negative
dispersion mirror (schematic drawing)

LAYERTEC offers ultrafast laser optics with different bandwidths.
This catalog shows optics for the wavelengths range of the Ti:Sapphire laser in three chapters, each representing a characteristic
bandwidth of the optics: standard components with a bandwidthof about 120 nm, broadband components (bandwidth about
300 nm) and octave spanning components.

Moreover, silver mirrors for fs applications are presented which offer the broadest low-GDD bandwidth available.
Please note that the GDD spectrum of a dielectric negative dispersion mirror is not a flat graph. All types of negative dispersion mirrors
exhibit oscillations in the GDD spectrum. These oscillations are small for standard bandwidths. However, broadband and ultra-broadband
negative dispersion mirrors exhibit strong GDD oscillations. Considerable reduction of these oscillations can be achieved by using mirror
pairs consisting of mirrors with carefully shifted GDD oscillations. Figure 3 shows a schematic drawing of said mirror pair and the corresponding GDD spectra.
It is also possible to use negative dispersion mirrors with high values of negative GDD for pulse compression. These so-called Gires-Tournois-Interferometer (GTI) mirrors (see page 64 f.) are successfully used in Ti:Sapphire lasers, Yb:YAG and Yb:KGW oscillators and Er:Fiber lasers.
Pulse compression in Yb:YAG and Yb:KGW oscillators provides pulses of some hundred femto-seconds pulse length. For each wavelength,components with different amounts of negative GDD are presented on the following pages. Besides these optics for the spectral rangeof the Ti:Sapphire fundamental and for the very promising Yb:YAG and Yb:KGW lasers, LAYERTEC also offers optics for the harmonics ofthis radiation down to the VUV wavelength range, optics for ultrafast lasers in the 1500 nm-range and especially designed optics for highpower ultra-short pulse lasers. LAYERTEC has its own capabilities for design calculation and also for GDD-measurements in the wavelength
range from 250 to 1700 nm.

35Ultrafast Laser Optics
Introduction to Ultrafast Laser Optics

GDD spectrum of mirror 2

GDD [fs2]

GDD [fs2]

GDD spectrum of mirror 1
150
120
90
60
30
0
-30
-60
-90
-120
-150

550

650

750

850

950

1050

150
120
90
60
30
0
-30
-60
-90
-120
-150
550

650

750

850

950

1050

wavelength [nm]wavelength [nm]average GDD spectrum

GDD [fs2]

mirror 2

mirror 1

150
120
90
60
30
0
-30
-60
-90
-120
-150

550

650

750

850

950

1050

wavelength [nm]Figure 3: Schematic drawing of a negative dispersion mirror pair

GDD and TOD
If a pulse is reflected by a dielectric mirror, i.e. a stack of alternating high and low refractive index layers, there will be a phase shift between
the original and the reflected pulse resulting from the time which it takes the different Fourier components of the pulse to pass through thelayer system of the mirror. In general, the phase shift Φ(ω) near the center frequency ω0 may be expanded in a Taylor series for frequencies
near ω0:Φ (ω) = Φ (ω0) + Φ´ (ω0) (ω –ω0) + Φ´´(ω0) (ω – ω0)²/2 + Φ´´´(ω0) (ω – ω0)3/6 + …
The derivatives are, respectively, the Group Delay (GD) Φ´(ω0), the Group Delay Dispersion (GDD) Φ´´(ω0) and the Third Order Dispersion(TOD) Φ´´´(ω0). More strictly speaking, this expansion is only useful in an exactly soluble model, for the propagation of a transform limited
Gaussian pulse and for pure phase dispersion. For extremely short pulses and combinations of amplitude and phase dispersion numericalcalculations may be necessary. Nevertheless, this expansion clearly shows the physical meaning of the single terms:
Assuming the phase shift is linear in frequency (i.e. GD ≠ 0, GDD = 0 and TOD = 0 over the pulse bandwidth), the reflected pulse is delayedin time by the constant group delay and, of course, scaled by the amplitude of reflectance R. The pulse spectrum will remain undistorted.
If GDD ≠ 0, two important effect are observed:• The reflected pulse is temporally broadened. This broadening effect depends only on the absolute value of the GDD. LAYERTEC offers “low GDD mirrors”, i.e. mirrors with |GDD| < 20 fs² over a given wavelength range, which guarantee the preservation of thepulse shape when the pulse is reflected by these mirrors.
• Moreover, the pulse becomes “chirped”, i.e. it changes its momentary frequency during pulse time. This effect depends on the signof the GDD, so that the momentary frequency may become higher (up-chirp, GDD > 0) or lower (down-chirp, GDD < 0). This allows
to compensate positive GDD effects of nonlinear optical elements by using negative GDD mirrors.
The TOD determines also pulse length and pulse shape (distortion of the pulse) and becomes a very important factor at pulse lengths of
20 fs and below.

References
R. Holzwarth, M. Zimmermann, Th. Udem, T.W. Hänsch, P. Russbüldt, K. Gäbel, R. Poprawe, J.C. Knight, W.J. Wadsworth and P.St.J. Russell:“White-light frequency comb generation with a diode-pumped Cr:LiSAF laser”; Optics Letters, Vol. 26, No.17 (2001), p. 1376 – 1378
Y.-S. Lim, H.-S. Jeon, Y.-C. Noh, K.-J. Yee, D.S. Kim, J.-H. Lee, J.-S. Chang, J.-D. Park: “Journal of the Korean Physical Society”; Vol. 40, No.5 (2002),
p. 837 – 843
G. Tempea, V. Yakovlev and F. Krausz: “Interference coatings for Ultrafast Optics”; in: N. Kaiser, H.K. Pulker (eds.), “Optical Interference Coatings“;Springer-Verlag Berlin Heidelberg 2003, p. 393 – 422 and the references therein36Ultrafast Laser Optics
Standard Ultrafast Laser Optics (120 – 150 nm Bandwidth)Standard Ultrafast Laser Optics (120 – 150 nm Bandwidth)• The coatings shown here are calculated for a bandwidth of 120 – 150 nm in the wavelength range between 600 nm and 1000 nm• Very high reflectance of the mirrors (R > 99.99 %)• Spectral tolerance 1 %• In-house design calculation and GDD measurement capabilities• Center wavelength, GDD and TOD according to customer specifications• Measured GDD spectra available on request• All kinds of mirrors (e.g. Cavity mirrors, pump mirrors and turning mirrors)
LIDT Info
0.4 J/cm², 800 nm, 42 fs, 1 kHz, Ø 80 µm*
2 J/cm², 800 nm, 70 fs, 10 Hz, Ø 700 µm**
For high power mirrors see page 54 f.
***

Measurements were performed at Wigner Research Centre for Physics, Budapest
Measurements were performed at Helmholtz-Zentrum Dresden-Rossendorf

Cavity Mirrors AOI = 0°
a

b

R [%]

GDD [fs2]

AOI = 0°

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

600

650

700

750

800

850

900

950

1000

AOI = 0°
200
160
120
80
40
0
-40
-80
-120
-160
-200

600

650

700

wavelength [nm]

750

800

850

900

950

1000

wavelength [nm]Figure 1: Reflectance and GDD spectra of a standard low dispersion ultrafast laser mirrora) Reflectance vs. wavelengthb) GDD vs. wavelength

All types of mirrors are also available with negative GDD (e.g. -40 fs²). For high dispersion mirrors see page 39.

Pump Mirrors AOI = 0°
R
100
90
80
70
60
50
40
30
20
10
0
480

R (99 – 100 %)AOI = 0°b

GDD [fs2]

R [%]

a

530

580

630

680

730

780

830

880

930

980

AOI = 0°
200
160
120
80
40
0
-40
-80
-120
-160
-200
600

wavelength [nm]

650

700

750

800

850

900

950

1000

wavelength [nm]Figure 2: Reflectance and GDD spectra of a standard low dispersion pump laser mirrora) Reflectance vs. wavelengthb) GDD vs. wavelength37

Ultrafast Laser Optics
Standard Ultrafast Laser Optics (120 – 150 nm Bandwidth)

Turning Mirrors AOI = 45°a

Rp

AOI = 45°

b

R [%]

GDD [fs2]

Rs

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

600

650

700

750

800

850

900

950

1000

GDDs
200
160
120
80
40
0
-40
-80
-120
-160
-200
600

650

700

750

wavelength [nm]

800

850

GDDp AOI = 45°

900

950

1000

wavelength [nm]Figure 3: Reflectance and GDD spectra for a standard low dispersion turning mirror (bandwidth Ru (45°) > 99.9 % ≈ 160 nm)a) Reflectance vs. wavelengthb) GDD vs. wavelength

Output Couplers AOI = 0°
R = 98 %
100
98
96
94
92
90
88
86
84
82
80

R = 95 %R = 90 %AOI = 0°b

GDD [fs2]

R [%]

a

700 720

740

760

780

800

820

840

860

880

900

50
40
30
20
10
0
-10
-20
-30
-40
-50

700 720740

reflected beamtransmitted beam

AOI = 0°

760

820

880

780

wavelength [nm]

800

840

860

900

wavelength [nm]Figure 4: Reflectance and GDD spectra of output couplers with a bandwidth of 120 nma) Reflectance spectra of several standard output couplersb) GDD spectra of the output coupler with R = 98 %; GDD spectra are similar for all levels of reflectanceBeam Splitters for p-polarized light at AOI = 45°
Rp = 66 %
100
90
80
70
60
50
40
30
20
10
0
650

Rp = 50 %Rp = 33 %AOI = 45°b

GDD [fs2]

R [%]

a

680

710

740

770

800

830

860

890

920

950

50
40
30
20
10
0
-10
-20
-30
-40
-50
650

680

710

reflected beamtransmitted beam

AOI = 45°

740

830

920

770

wavelength [nm]Figure 5: Reflectance and GDD spectra of beam splitters for p-polarized lighta) Reflectance spectra of several standard beam splitters and p-polarized lightb) GDD spectra of the beam splitter with R = 50 %; the GDD spectra are similar for all levels of reflectance

38

800

wavelength [nm]

860

890

950

Ultrafast Laser Optics
Standard Ultrafast Laser Optics (120 – 150 nm Bandwidth)

Beam Splitters for s-polarized light at AOI = 45°
Rs = 66 %
100
90
80
70
60
50
40
30
20
10
0

Rs = 50 %Rs = 33 %AOI = 45°b

GDD [fs2]

R [%]

a

700

740

780

820

860

900

reflected beam
50
40
30
20
10
0
-10
-20
-30
-40
-50
700

740

780

wavelength [nm]transmitted beam

820

AOI = 0°860

900

wavelength [nm]Figure 6: Reflectance and GDD spectra of beam splitters for s-polarized lighta) Reflectance spectra of several standard beam splitters and s-polarized lightb) GDD spectra of the beam splitter with R = 50 %; the GDD spectra are similar for all levels of reflectance• Reflectance and transmittance of output couplers and beam
splitters can be adjusted according to customer specifications• Tolerances for output couplers:• R = 10 % … 70 % ± 2.5 %• R = 70 % … 90 % ± 1.5 %• R = 90 % … 95 % ± 0.75 %• R = 95 % … 98 % ± 0.5 %• R > 98 % ± 0.25 %• R > 99 % ± 0.1 %• Standard AR coatings:• AOI = 0°: R < 0.2 %• AOI = 45°: Rs or Rp < 0.2 %• AOI = 45°: Rs ≈ Rp ≈ 0.5 %• In case of p-polarization, uncoated rear side possible,
Rp (Fused Silica, 45°) ≈ 0.6 %Negative Dispersion Mirrors AOI = 0°a

AOI = 0°b

100.0

GDD [fs2]

R [%]

99.8
99.6
99.4
99.2
99.0
600

700

800
wavelength [nm]

900

1000

AOI = 0°
200
160
120
80
40
0
-40
-80
-120
-160
-200

600

650

700

750

800

850

900

950

1000

wavelength [nm]Figure 7: Reflectance spectra of aluminum mirrorsa) Reflectance vs. wavelengthb) GDD vs. wavelength39

Ultrafast Laser Optics
Standard Ultrafast Laser Optics (120 – 150 nm Bandwidth)High Dispersion Mirrors AOI = 0°
Recent advances in design calculation and process control enable LAYERTEC to offer high dispersion mirrors for pulse compression in advanced Ti:Sapphire lasers. These mirrors and mirror pairs show spectral bandwidths of 100 nm – 300 nm and negative GDD values of some
hundred fs². These mirrors can be used for pulse compression. Compared to prism compressors, high dispersion mirrors reduce the intra
cavity losses resulting in higher output power of the laser.
All high dispersion mirrors are designed according to customer specification. Please specify the amount GD which is to be compensated.
a

AOI = 0°b

AOI = 0°

99.6

-200
GDD [fs2]

0

R [%]

100.0

99.2
98.8
98.4

-400
-600
-800

98.0
680

730

780

830

880

930

980

1030

1080

-1000
730

750

770

wavelength [nm]

c

790

810

830

850

870

wavelength [nm]Measurement
1000
750

GDD [fs2]

500
250
0
-250
-500
-750
-1000

730

750

770

790

810

830

850

870

wavelength [nm]Figure 8: Reflectance and GDD spectra of a high dispersion mirror witha bandwidth of 120 nm and a GDD of -450 ± 100 fs² in the
800 nm rangea) Reflectance vs. wavelengthb) Calculated GDD vs. wavelengthc) Measured GDD vs. wavelength

Matching measured and calculated GDD spectra prove the reliability of the coating process.

High Dispersion Mirror Pairs AOI = 0°amirror A

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
600

mirror B

AOI = 0°

mirror A

mirror B

AOI = 0°

100

R [%]

GDD [fs2]

50
0
-50
-100
-150
700

800

900

1000

1100

wavelength [nm]

c

b

-200

720

770

820

870

920

970

wavelength [nm]average per bounce

Measurement50

GDD [fs2]

0
-50
-100
-150
-200
-250
720

760

800

840

880

wavelength [nm]

40

920

960

1000

Figure 9: Reflectance and GDD spectra of a high dispersion mirror
pair with a bandwidth of 200 nm and an average GDD of-120 ± 40 fs² per bounce in the 800 nm rangea) Reflectance vs. wavelengthb) Calculated GDD vs. wavelengthc) Measured GDD vs. wavelength1020

Ultrafast Laser Optics
Standard Ultrafast Laser Optics (120 – 150 nm Bandwidth)

This very special type of optical coatings can be used to compensate the third order dispersion which results from laser crystals, substrates
or dispersive elements like prisms or gratings. Positive as well as negative TOD can be achieved with this type of coatings. All coatings
are optimized for nearly constant TOD which means TOD oscillations in the order of some hundreds of fs3. Please note that without TOD
optimization these oscillations are on the order of some thousands of fs3.

Thin Film Polarizers for AOI = 55°
Rs
100
90
80
70
60
50
40
30
20
10
0

Rp

AOI = 55°b

GDD (Rs)GDD (Tp)

AOI = 55°

830

850

360
270
180
GDD [fs2]

R [%]

a

90
0
-90
-180
-270

750

770

790

810

830

-360

850

750

770

wavelength [nm]

790

810

wavelength [nm]Figure 10: Reflectance and GDD spectra of a standard TFP (AOI = 55° to use the Brewster’s angle for the transmitted p-polarized light)a) Reflectance vs. wavelengthb) GDD vs. wavelength

Thin Film Polarizers for AOI = 65°
The bandwidth of thin film polarizers can be extended if large angles of incidence are used. As shown in figure 11a polarizer bandwidth aslarge as 100 nm can be achieved. However, this is combined with a reduced reflectance for the s-polarized light.
Rs
100
90
80
70
60
50
40
30
20
10
0

Rp

AOI = 65°

GDD (Rs)GDD (Tp)

AOI = 65°

830

850

360
270
180
90
0
-90
-180
-270
750

770

790

810

830

850

wavelength [nm]

-360

750

770

790

810

wavelength [nm]

c

R [%]

b

GDD [fs2]

R [%]

a

AOI = 65°
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0

700

740

780

820

wavelength [nm]

860

900

Figure 11: Reflectance and GDD spectra of a TFP (AOI = 65° to achieve a
low GDD for Rs and Tp, bandwidth ≈ 40 nm)a) Reflectance vs. wavelengthb) GDD vs. wavelengthc) Rear side ARp (65°, 750 – 850 nm)

41Ultrafast Laser Optics
Standard Ultrafast Laser Optics (120 – 150 nm Bandwidth)Thin Film Polarizers for AOI = 80°
Rs
100
90
80
70
60
50
40
30
20
10
0

Rp

AOI = 80°b

GDD (R) [fs2]

R [%]

a

650

700

750

800

850

900

950

GDD (Rs)
100
80
60
40
20
0
-20
-40
-60
-80
-100

650

700

750

wavelength [nm]GDD(T) [fs2]

c

700

750

800

850

900

950

1000

wavelength [nm]

GDD (Ts)
100
80
60
40
20
0
-20
-40
-60
-80
-100
650

800

AOI = 80°

GDD (Tp)

850

AOI = 80°

900

950

wavelength [nm]Figure 12: Reflectance and GDD spectra of a TFP (AOI = 80°, lower Rs-value
to achieve a low GDD for Rs and Tp, bandwidth ≈ 150 nm)a) Reflectance vs. wavelengthb) GDD of the reflected light vs. wavelengthc) GDD of the transmitted light vs. wavelength

Non-polarizing Beam Splitters for AOI = 45°
Rs
75
70
65
60
55
50
45
40
35
30
25

Rp

AOI = 45°b

GDD(R) [fs2]

R [%]

a

760

770

780

790

800

810

820

830

wavelength [nm]c

GDD (Ts)GDD (Rs)
200
160
120
80
40
0
-40
-80
-120
-160
-200

760

770

780

790

800

GDD (Rp) AOI = 45°

810

820

830

wavelength [nm]

GDD (Tp)

AOI = 45°360
270
GDD(T) [fs2]

180
90
0
-90
-180
-270
-360

760

770

780

790

800

wavelength [nm]

42

810

820

830

Figure 13: Reflectance and GDD spectra of a non-polarizing beam splittera) Reflectance vs. wavelengthb) GDD of the reflected light vs. wavelengthc) GDD of the transmitted light vs. wavelengthUltrafast Laser Optics
Standard Ultrafast Laser Optics (120 – 150 nm Bandwidth)

Antireflection Coatings
AOI = 0°
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0

Rp

AOI = 45°

2.0
1.5
1.0
0.5
600

680

760

840

920

1000

Rs

650

750

850
wavelength [nm]

0

600

680

760

840

920

1000

wavelength [nm]

c

R [%]

Rs
2.5

wavelength [nm]

2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0

b

R [%]

R [%]

a

AOI = 0°950

Figure 14: Reflectance of different antireflection coatingsa) AOI = 0°b) AOI = 45° Rs = Rp ≈ 0.5 %c) AOI = 45° Rs < 0.2 % (only possible for s- or p-polarized light)

Broadband antireflection coatings for AOI = 0° or a single polarization at AOI > 0° with R < 0.1 % on request.

43

Ultrafast Laser Optics
Broadband Ultrafast Laser Optics (200 – 300 nm Bandwidth)

Broadband Ultrafast Laser Optics (200 – 300 nm Bandwidth)• The coatings shown here are calculated for the wavelength range 700 – 1000 nm.
Similar coatings are available for 600 – 900 nm and 650 – 950 nm.
• Very high reflectance of the mirrors (R > 99.8 % … R > 99.95 % depending on the design)• Center wavelength, bandwidth, GD, GDD and TOD according to customer specifications• Spectral tolerance ± 1 %• In-house design calculation and GDD measurement capabilities• GDD measurement reports are included in the delivery
LIDT Info≈ 0.1 J/cm², 800 nm, 150 fs
Measurements were performed at Laser Zentrum Hannover

Mirror Pairs for AOI = 0°amirror B

AOI = 0°b

GDD [fs2]

mirror A

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

550

650

750

850

950

1050

mirror A
200
160
120
80
40
0
-40
-80
-120
-160
-200

550

650

wavelength [nm]mirror B

750

average

850

AOI = 0°

950

1050

wavelength [nm]Figure 1: Reflectance and GDD spectra of a negative dispersion laser mirror paira) Reflectance vs. wavelengthb) GDD vs. wavelength

Mirror pairs show a very smooth average GDD spectrum, although the single broadband mirrors exhibit strong GDD oscillations. Pump
mirror pairs, i.e. mirror pairs with at least one mirror showing high transmittance between 514 – 532 nm, are also available.

Turning Mirrors for s-polarized Light at AOI = 45°a

AOI = 45°b

GDD [fs2]

Rs

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

650

700

750

800

850

900

950

1000

1050

GDD (Rs)
200
160
120
80
40
0
-40
-80
-120
-160
-200

650

wavelength [nm]Figure 2: Reflectance and GDD spectra of a broadband turning mirror for s-polarized lighta) Reflectance vs. wavelengthb) GDD vs. wavelength

44

700

750

800

850

900

wavelength [nm]950

AOI = 45°

1000

1050

Ultrafast Laser Optics
Broadband Ultrafast Laser Optics (200 – 300 nm Bandwidth)

Turning Mirrors for p-polarized Light at AOI = 45°a

AOI = 45°

b

R [%]

GDD [fs2]

Rp

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
650

700

750

800

850

900

950

1000

1050

GDD (Rp)
200
160
120
80
40
0
-40
-80
-120
-160
-200

650

700

750

800

wavelength [nm]

850

900

AOI = 45°

950

1000

1050

wavelength [nm]Figure 3: Reflectance and GDD spectra of a broadband turning mirror for p-polarized lighta) Reflectance vs. wavelengthb) GDD vs. wavelength

Output Couplers for AOI = 0°
R = 95 %
100
95
90
85
80
75
70
65
60
55
50

R = 80 %R = 70 %AOI = 0°b

GDD [fs2]

R [%]

a

680

730

780

830

880

930

980

1030

reflected beam
100
80
60
40
20
0
-20
-40
-60
-80
-100

680

730

780

wavelength [nm]830transmitted beam

880

930

AOI = 0°

980

1030

wavelength [nm]c

AOI = 0°
2.0

R [%]

1.6
1.2
0.8
0.4
0
680

730

780

830

880

930

980

1030

wavelength [nm]Figure 4: Reflectance and GDD spectra of several broadband output
couplersa) Reflectance spectra of several broadband output couplersb) GDD spectra of the output coupler with R = 80 %;the GDD spectra are similar for all levels of reflectancec) Reflectance spectrum of a broadband AR coating
AR (0°, 680 – 1030 nm) < 0.5 %Beam Splitters for p-polarized Light at AOI = 45°
Rp = 67 %
100
90
80
70
60
50
40
30
20
10
0
600

Rp = 50 %Rp = 33 %AOI = 45°breflected beamtransmitted beam AOI = 45°90
45
GDD [fs2]

R [%]

a

0
-45

700

800

900

wavelength [nm]

1000

1100

-90
650

700

750

800

850

900

950

1000

1050 1100

wavelength [nm]Please turn page for image description

45

Ultrafast Laser Optics
Broadband Ultrafast Laser Optics (200 – 300 nm Bandwidth)c

ARp (45°)

Rp (45°, uncoated backside)

AOI = 45°

1.00

R [%]

0.75
0.50
0.25
0.00
650

700

750

800

850

900

950

1000

1050 1100

wavelength [nm]Figure 5: Reflectance and GDD spectra of several broadband beam
splitters for p-polarized lighta) Reflectance of several broadband beam splitters forp-polarizationb) GDD spectra for the 50 % beam splitterc) Reflectance spectrum of a broadband AR coating forp-polarized light

Beam Splitters for s-polarized Light at AOI = 45°
Rs = 67 %
100
90
80
70
60
50
40
30
20
10
0
600

Rs = 50 %Rs = 33 %AOI = 45°breflected beamtransmitted beam

AOI = 45°

15
10
GDD [fs2]

R [%]

a

5
0
-5
-10

700

800

900

1000

-15
650

1100

700

750

800

wavelength [nm]c

ARs (45°)

850

900

950

1000

1050 1100

wavelength [nm]Rs (45°, uncoated backside) AOI = 45°

10.0

R [%]

7.5
5.0
2.5
0.0
650

700

750

800

850

900

950

1000

1050 1100

wavelength [nm]Figure 6: Reflectance and GDD spectra of several broadband beam
splitters for s-polarized lighta) Reflectance of several broadband beam splitters fors-polarizationb) GDD spectra for the 50 % beam splitterc) Reflectance spectrum of a broadband AR coating fors-polarized light

Negative Dispersion Pump Mirror Pairs for AOI = 0°
mirror A
mirror A (99 – 100 %)

100
90
80
70
60
50
40
30
20
10
0

mirror B
mirror B (99 – 100 %)AOI = 0°b

GDD [fs2]

R [%]

a

500

600

700

800

900

1000

1100

200
160
120
80
40
0
-40
-80
-120
-160
-200
600

650

700

mirror A

mirror B

average

750

850

950

wavelength [nm]Figure 7: Reflectance and GDD spectra of a negative dispersion pump mirror pair (mirror B without HT-option)a) Reflectance vs. wavelengthb) GDD vs. wavelength

46

800

900

wavelength [nm]AOI = 0°1000 1050 1100

Ultrafast Laser Optics
Broadband Ultrafast Laser Optics (200 – 300 nm Bandwidth)Thin Film Polarizers for AOI = 70°
Rs
100
90
80
70
60
50
40
30
20
10
0

Rp

AOI = 70°b

GDD [fs2]

R [%]

a

625

675

725

775

825

875

925

GDD Rs
25
20
15
10
5
0
-5
-10
-15
-20
-25

625

675

725

wavelength [nm]c775

GDD Tp825

AOI = 70°

875

925

wavelength [nm]Rs

Rp

AOI = 70°

60
50

R [%]

40
30
20
10
0

550

600

650

700

750

800

850

900

950

wavelength [nm]Figure 8: Reflectance and GDD spectra of a TFP (AOI = 70°), lower Rs toachieve “zero” GDD for Rs and Tp, bandwidth ≈ 300 nma) Reflectance vs. wavelengthb) GDD vs. wavelengthc) Rear side AR coating for s-polarized light. Please note that thiscoating results in R ≈ 15 % for the p-polarized component. As
an AR coating for the p-polarization LAYERTEC suggests theuse of the design from figure 8a.

High Negative Dispersion Mirror Pairs for AOI = 0°amirror A

mirror B

AOI = 0°

mirror A

mirror B

AOI = 0°GD [fs]

120
90
60
30
500

700

900

1100

wavelength [nm]

c

b
150

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

Measurement

0
600

700

800

900

1000

wavelength [nm]average

AOI = 0°250

GDD [fs2]

125
0
-125
-250
-375
-500
660

710

760

810

wavelength [nm]

860

910

Figure 9: Reflectance, GD and GDD spectra of a high dispersion mirror
pair with a bandwidth of 250 nm and an average GDD of-180 fs² ± 40 fs² per bounce in the 800 nm rangea) Reflectance vs. wavelengthb) Calculated GD vs. wavelengthc) Measured GDD vs. wavelength47

Ultrafast Laser Optics
Broadband Ultrafast Laser Optics (200 – 300 nm Bandwidth)

Mirror Pairs with Optimized Third Order Dispersion for AOI = 0°amirror B

AOI = 0°b

R [%]GDD [fs2]

mirror A

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

550

650

750

850

950

1050

mirror A
250
200
150
100
50
0
-50
-100
-150
-200
-250

650

wavelength [nm]c

mirror A

mirror B

700

750

mirror B

800

850

average

900

AOI = 0°

950

1000

wavelength [nm]average

AOI = 0°

10000

TOD [fs3]

5000
0

-5000
-10000

650

700

750

800

850

900

950

1000

wavelength [nm]Figure 10: Reflectance, GDD and TOD spectra of a mirror pair optimized forbroadband low third order dispersiona) Reflectance vs. wavelengthb) GDD vs. wavelengthc) TOD vs. wavelength

The mirror pair shows very smooth GDD and TOD spectra, although the single mirrors exhibit considerable GDD and TOD oscillations.

Special Features• GDD of high dispersive mirrors between -50 fs² and -500 fs²• Very high reflectance• Center wavelength, bandwidth and GDD according to customer specifications• Please note that bandwidth and GDD are closely connected. High values of negative GDD result in a very narrow bandwidth• Spectral tolerance ± 1 %• In-house design calculation and measurement capabilities (GDD 250 – 1700 nm, reflectance measurement by CRD 220 – 1800 nm)
LIDT Info≈ 0.1 J/cm², 800 nm, 150 fs
Measurements were performed at Laser Zentrum Hannover48

Ultrafast Laser Optics
Octave Spanning Ultrafast Laser Optics (400 – 500 nm Bandwidth)

Octave Spanning Ultrafast Laser Optics(400 – 500 nm Bandwidth)• The coatings shown here are calculated for the wavelength range of one octave (e.g. 550 – 1100 nm). Similar coatings are possible
for other wavelength ranges.
• Center wavelength, bandwidth, GDD and reflectance of output couplers and beam splitters according to customer specifications• Spectral tolerance ± 1 %• In-house design calculation and GDD measurement capabilities• GDD measurement reports are included in the delivery
LIDT Info≈ 0.1 J/cm², 800 nm, 150 fs
Measurements were performed at Laser Zentrum Hannover

Negative Dispersion Laser Mirror Pairs for AOI = 0°
Mirror pairs designed by LAYERTEC show a very smooth average GDD spectrum even though the single broadband mirrors exhibit strong
GDD oscillations.
amirror A

mirror B

AOI = 0°b

mirror A

mirror B

average

AOI = 0°500

GDD [fs2]

250

R [%]

100.0
99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

0
-250

500

600

800

700

1000

900

-500
550

1100

650

wavelength [nm]

750

850

950

1050

wavelength [nm]Figure 1: Reflectance and GDD spectra of an ultra broadband negative dispersion laser mirror paira) Reflectance vs. wavelengthb) GDD vs. wavelength

Negative Dispersion Pump Mirror Pairs for AOI = 0°
The pump mirror pair consists of two mirrors which both show a region of high transmittance around 500 nm.

100
90
80
70
60
50
40
30
20
10
0
450

mirror A
mirror A (99 – 100 %)mirror B
mirror B (99 – 100 %)AOI = 0°b

mirror A

mirror B

AOI = 0°

950

1050

1150

100
75
GD [fs]

R [%]

a

50
25

550

650

750

850

950

wavelength [nm]

1050

1150

1250

0

650

750

850

wavelength [nm]Please turn page for image description

49

Ultrafast Laser Optics
Octave Spanning Ultrafast Laser Optics (400 – 500 nm Bandwidth)cmirror A

mirror B

average

AOI = 0°500

GDD [fs2]

250
0
-250
-500
700

750

800

850

900

950

1000

1050

1100 1150

wavelength [nm]Figure 2: Reflectance and GDD spectra of an ultra broadband negative
dispersion pump mirror paira) Reflectance vs. wavelengthb) GD vs. wavelengthc) GDD vs. wavelength

Negative Dispersion Turning Mirror Pairs for p-polarized Light for AOI = 0°
mirror A
100
99
98
97
96
95
94
93
92
91
90
400

mirror B

AOI = 0°b

GDD [fs2]

R [%]

a

500

600

700

800

900

1000

mirror A
200
160
120
80
40
0
-40
-80
-120
-160
-200

400

500

mirror B

600

wavelength [nm]average

700

AOI = 0°800

900transmitted beam

AOI = 0°wavelength [nm]Figure 3: Reflectance and GDD spectra of an ultra broadband turning mirror pair for p-polarized lighta) Reflectance vs. wavelengthb) GDD vs. wavelength

Output Couplers for AOI = 0°
AOI = 0°
100
90
80
70
60
50
40
30
20
10
0

120
60
0
-60
-120
520

620

720

820

920

1020

1120

1220

-180
520

620

720

820

920

1020

1120

wavelength [nm]

c

R [%]

reflected beam180

wavelength [nm]AOI = 0°
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
420

520

620

720

820

920

wavelength [nm]50b

GDD [fs2]

R [%]

a

1020

1120

1220 1320

Figure 4: Reflectance and GDD spectra of an ultra broadband output
coupler with R = 85 % ± 3 %a) Reflectance vs. wavelengthb) GDD vs. wavelengthc) Rear side octave spanning AR coating

1220

Ultrafast Laser Optics
Octave Spanning Ultrafast Laser Optics (400 – 500 nm Bandwidth)

Beam Splitters for p-polarized Light at AOI = 45°
Rp
100
90
80
70
60
50
40
30
20
10
0
450

AOI = 45°breflected beamtransmitted beam AOI = 45°

180
120
GDD [fs2]

R [%]

a

60
0
-60
-120

550

650

750

850

950

1050

-180
450

1150

550

650

wavelength [nm]

750

850

950

1050

1150

wavelength [nm]cRp

AOI = 45°

5.0

R [%]

4.0
3.0
2.0
1.0
0
450

550

650

750

850

950

1050

1150

wavelength [nm]Figure 5: Reflectance and GDD spectra of an ultra broadband beam splitter for p-polarized light with Rp = 50 % ± 4 %a) Reflectance vs. wavelengthb) GDD vs. wavelengthc) Rear side octave spanning AR coating for p-polarized light

Beam Splitters for s-polarized Light at AOI = 45°
Rs = 50 % ±5 %
100
90
80
70
60
50
40
30
20
10
0
475

AOI = 45°

R [%]transmitted beam

AOI = 45°

10
0
-10

575

675

775

875

975

1075

1175

Rs

550

650

750

850

950

wavelength [nm]

-20
475

575

675

775

875

975

1075

1175

wavelength [nm]c450reflected beam
20

wavelength [nm]

10
9
8
7
6
5
4
3
2
1
0

b

GDD [fs2]

R [%]

a

1050

1150

AOI = 45°1250 1350

Figure 6: Reflectance and GDD spectra of an ultra broadband beam splitter for s-polarized light with Rs = 50 % ± 5 %a) Reflectance vs. wavelengthb) GDD vs. wavelengthc) Rear side octave spanning AR coating for s-polarized light51

Ultrafast Laser Optics
Silver Mirrors for Ultrafast Lasers (550 – 1100 nm)

Silver Mirrors for Ultrafast Lasers (550 – 1100 nm)
Silver Mirrors Optimized for Laser Applications
AOI = 0°
100
99
98
97
96
95
94
93
92
91
90
600

b

AOI = 0°10
5GDD [fs2]

R [%]

a

0
-5

650

700

750

800

850

900

950

-10

1000

600

650

700

wavelength [nm]

750

800

850

900

950

1000

wavelength [nm]Figure 1: Reflectance and GDD spectra of a silver mirror optimized for use with ultrafast-lasers in the wavelength range 600 – 1000 nm (AOI = 0°)a) Reflectance vs. wavelengthb) GDD vs. wavelength
Rs
100
99
98
97
96
95
94
93
92
91
90

Rp

Ru

AOI = 45°b

GDD [fs2]

R [%]

a

600

650

700

750

800

850

900

950

1000

s-pol.
10
8
6
4
2
0
-2
-4
-6
-8
-10
600

650

wavelength [nm]

700

750

800

850

p-pol.

AOI = 45°

900

950

1000

wavelength [nm]Figure 2: Reflectance and GDD spectra of a silver mirror optimized for use with ultrafast-lasers in the wavelength range 600 – 1000 nm (AOI = 45°)a) Reflectance vs. wavelengthb) GDD vs. wavelength

Special Features• High reflectance in the VIS and NIR• Very broad reflectance band with GDD ≈ 0 fs²• Silver mirrors with defined transmittance (e.g. 0.01 %)exhibit high LIDT (see table) and the same reflectance and
GDD values as shown in figure 1 and figure 2• Lifetimes of more than 10 years have been demonstrated innormal atmosphere• Highly stable optical parameters due to sputtered protective
layers• Easy to clean (tested according to MIL-M-13508C § 4.4.5)• Extremely low scattering losses(total scattering TS ≈ 30 ppm in the VIS and NIR)

Stock of standard components• Standard and fs-optimized protected silver on substrates with
Ø = 12.7 mm, Ø = 25 mm and Ø = 50 mm:• Plane• Plano/concave and plano/convex with a variety of radii
between 10 mm and 10 000 mm• Other sizes, shapes, radii and coatings for other wavelength
ranges on request

Table 1: Technical data of silver mirrors for ultrafast lasers

Coating

Reflectance*

Wavelength Range

LIDT**

fs-optimized protected silver

R = 96.5 … 98.5 %600 – 1000 nm

0.38 J/cm²

Enhanced silver 800 nm

R > 99 %700 – 900 nm

0.37 J/cm²

Broadband enhanced silver

R = 98 … 98.5 %600 – 1200 nm

0.24 J/cm²

Partially transparent silver

R = 96.5 … 98.5 %600 – 1000 nm

0.22 J/cm²

*
**

52

For unpolarized light at AOI = 45°
Measurements were performed at Laser Zentrum Hannover according to ISO 11254 measurement conditions: pulse duration:
150 fs, 30000 pulses, repetition rate: 1 kHz, λ = 800 nm

Ultrafast Laser Optics
Silver Mirrors for Ultrafast Lasers (550 – 1100 nm)

Silver Mirrors with Enhanced Reflectance
The reflectance of silver mirrors can be enhanced by an additional dielectric coating. The bandwidth of the enhanced reflectance must
be exactly specified. Outside this band, the reflectance of the mirror may be lower than that of a standard silver mirror. For the use with
fs-lasers, the additional dielectric coating must be optimized for high reflectance and low GDD. The following figures show examples forsilver mirrors with enhanced reflectance at a specified wavelength (figure 3 and figure 4) and over the wavelength range of the Ti:Sapphirelaser (figure 5). Enhanced silver mirrors can also be designed for a defined transmittance (e.g. T = 0.01 %).
astandard

enhanced 1

enhanced 2enhanced 3

AOI = 0°b

100

GDD [fs2]

R [%]

99
98
97
96
95
650

700

750

800

850

900

950

1000

1050 1100

enhanced 1
180
150
120
90
60
30
0
-30
-60
-90
-120
-150
-180

650

700

750

wavelength [nm]enhanced 2

800

850

900

enhanced 3

950

AOI = 0°1000

1050 1100

p-pol.

AOI = 45°

900

950

p-pol.

AOI = 45°

900

950

wavelength [nm]Figure 3: Reflectance and GDD spectra of silver mirrors with different designs for enhanced reflectance around 850 nm (AOI = 0°)a) Reflectance vs. wavelengthb) GDD vs. wavelength
Rs
100
99
98
97
96
95
94
93
92
91
90
600

Rp

Ru

AOI = 45°bs-pol.
40
30
20

GDD [fs2]

R [%]

a

10
0
-10
-20
-30

650

700

750

800

850

900

950

-40
600

1000

650

700

wavelength [nm]

750

800

850

1000

wavelength [nm]Figure 4: Reflectance and GDD spectra of a silver mirror with enhanced reflectance around 800 nm (AOI = 45°)a) Reflectance vs. wavelengthb) GDD vs. wavelength
Rs
100
99
98
97
96
95
94
93
92
91
90
600

Rp

Ru

AOI = 45°bs-pol.
40
30
20

GDD [fs2]

R [%]

a

10
0
-10
-20
-30

700

800

900
wavelength [nm]

1000

1100

1200

-40
600

650

700

750

800

850

1000

wavelength [nm]Figure 5: Reflectance and GDD spectra of a silver mirror with enhanced reflectance in the wavelength range 600 – 1200 nm (AOI = 45°)a) Reflectance vs. wavelengthb) GDD vs. wavelength53

Ultrafast Laser Optics
High Power Ultrafast Laser Optics (550 – 1100 nm)

High Power Ultrafast Laser Optics (550 – 1100 nm)
Ultrafast lasers are widely used in measurement applications and materials science. Ultrafast lasers enable the machining of metals as well
as of dielectric materials by cold, i.e. non-thermal, processes. The most important feature of these treatment steps is the avoidance ofmelt. That is why pieces machined with ultrafast lasers are of high accuracy and do not require mechanical postprocessing. The demands
for efficient production processes drive the development of high power fs lasers. In most cases, these lasers show pulse lengths between
100 fs and 1 ps.
Moreover, high power ultrafast lasers with power levels in the terawatt and petawatt range become more and more important in basic
research on light material-interaction, particle physics and even for medical applications. The pulse duration of these lasers is considerably
shorter than that of lasers for material processing. Typical pulse durations range from 20 fs to 50 fs.
The laser types mentioned above require optics with high laser-induced damage thresholds (LIDT). High power coatings for ultrafast lasers
were the topic of a number of scientific investigations in the last years [1, 2]. Research institutes as well as optics manufacturers have spentmuch effort on the improvement of the LIDT of fs laser optics. LAYERTEC has dealt with this issue for more than 20 years.
The main result of these investigations mentioned above was that the LIDT of optical coatings in the fs regime is strongly related to theband gap of the coating materials as well as the coating designs. Materials with larger band gaps exhibit larger LIDT. However, there is atrade-off between damage threshold and bandwidth, as large band gaps also translate into a smaller difference of the refractive indices.
Thus, turning mirrors made of these materials only have a bandwidth of about 100 nm for p-polarized light at AOI = 45°. This bandwidthis sufficient for pulse lengths as low as 25 fs. Please note that all LAYERTEC high power designs are optimized for GDD < 50 fs².
high power GDD-Rs
broadband GDD-Rs

high power GDD-Rp
broadband GDD-Rp

AOI = 45°

R [%]

100.0
99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

b

GDD-R [fs2]

a

650

700

750

800

850

wavelength [nm]

900

950

1000

200
160
120
80
40
0
-40
-80
-120
-160
-200
650

high power GDD-Rs
broadband GDD-Rs

700

750

high power GDD-Rp
broadband GDD-Rp

800

850

900

AOI = 45°

950

1000

wavelength [nm]Figure 1: Reflectance and GDD spectra of a high power ultrafast laser turning mirror (solid lines) and a broadband ultrafast laser turning mirror (dashed lines)a) Reflectance vs. wavelengthb) GDD vs. wavelength

In contrast, materials with a large difference of the refractive indices may be used in order to achieve large bandwidths. Designs for standard low-GDD components exhibit medium LIDT values, whereas broadband designs result in low damage thresholds. This is also the casewhen considering mirrors with dispersion control, such as chirped mirror pairs or GTI mirrors. Here, bandwidth and phase requirements
outweigh LIDT. However, depending on the complexity of the overall constraints, some optimization of damage thresholds may be possible.
The investigations have also shown that LAYERTEC’s optimized silver mirrors possess significant LIDT values in the fs range. Another advantage of silver mirrors is their extremely broad zero-GDD reflectance band with reflectance up to 98.5 % at normal incidence. Even silver
mirrors with a defined transmission of 0.01 % exhibit considerable damage thresholds, especially with respect to dielectric ultra broadband
components. For more information on silver mirrors see page 52 f.

References[1] B. Mangote, L. Gallais, M. Commandré, M. Mende, L. O. Jensen, H. Ehlers, M. Jupé, D. Ristau, A. Melninkaitis, J. Mirauskas, V. Sirutkaitis,
S. Kicas, T. Tolenis, R. Drazdys: “Femto-second laser damage resistance of oxide and mixture oxide optical coatings”; Optics Letters 9 (Vol. 37), p. 14781480 (2012)[2] Raluca A. Negres, Christopher J. Stolz, Kyle R. P. Kafka, Enam A. Chowdhury, Matt Kirchner, Kevin Shea, Meaghan Daly: “40-fs broadband
low dispersion mirror thin film damage competition”; Proceedings Volume 10014, Laser-Induced Damage in Optical Materials 2016, 100140E (2016)54

Ultrafast Laser Optics
High Power Ultrafast Laser Optics (550 – 1100 nm)

Overview about Laser-Induced Damage Thresholds of Ultrafast Laser Optics
Table 1: Overview about LIDT data

Coating

Reflectance at 800 nm

LIDT

Pulse Duration, Repetition Rate

Single-wavelength AR coating**< 0.2 %

1.10 J/cm2 3)
1.20 J/cm2 2)

42 fs, 1 kHz
1 ps, 1 kHz

Broadband AR coating**< 0.5 %

1.20 J/cm2 2)

1 ps, 1 kHz

Unprotected gold

97.5 %

0.33 J/cm² 1)
0.33 J/cm2 2)

50 fs, 1 kHz
150 fs, 1 kHz

fs-optimized silver

98.5 %

0.38 J/cm2 1)
0.38 J/cm2 2)

50 fs, 1 kHz
150 fs, 1 kHz

Enhanced silver(600 – 1200 nm)

98.5 %

0.24 J/cm2 2)

150 fs, 1 kHz

Partially transparent silver(T = 0.01 % @ 800 nm)

98.5 %

0.22 J/cm2 2)

150 fs, 1 kHz

High power mirror for fs pulses> 99.5 %0.90 J/cm2 3)
3.60 J/cm2 4)

42 fs, 1 kHz
70 fs, 10 Hz

Enhanced silver (800 nm)

99.7 %

0.37 J/cm2 2)

150 fs, 1 kHz

Negative-dispersion mirrors*> 99.9 %0.10 J/cm2 2)

150 fs, 1 kHz> 99.9 %)0.15 J/cm2 1
0.10 J/cm2 2)

6 fs, 4 kHz
150 fs, 1 kHz

Standard low-GDD mirrors> 99.9 %0.50 J/cm2 3)
2.40 J/cm2 4)
0.30 J/cm2 2)0.55 J/cm2 2)

42 fs, 1 kHz
70 fs, 10 Hz
150 fs, 1 kHz
1 ps, 1 kHz

High power mirror for ps pulses> 99.9 %0.35 J/cm2 1)
0.44 J/cm2 2)0.65 J/cm2 2)

50 fs, 1 kHz
150 fs, 1 kHz
1 ps, 1 kHz

Broadband low-GDD mirrors*

1)
2)
3)
4)
*
**

Measurements were performed at Friedrich Schiller University Jena
Measurements were performed at Laser Zentrum Hannover
Measurements were performed at Wigner Research Centre for Physics, Budapest
Measurements were performed at Helmholtz-Zentrum Dresden-Rossendorf
A significant number of designs were tested. The LIDT values stated here are typical for the corresponding test conditions.
Self-focusing effects may destroy the substrate while the AR coating is still intact.

Figure 2: Laser-induced damage to a coated surface, diameter ≈ 750 µm

55Ultrafast Laser Optics
High Power Ultrafast Laser Optics (550 – 1100 nm)

R [%]Metallic High Power Mirrors

100
99
98
97
96
95
94
93
92
91
90

fs-optimized silver AOI = 0°

gold

650

700

750

800

850

900

950

1000

wavelength [nm]Figure 3: Reflectance spectra of unprotected gold and fs-optimized silver(optimized for high reflectance at 800 nm)

GDD [fs2]

GDD of High Power Ultrafast Laser Mirrors
standard low GDD
150
120
90
60
30
0
-30
-60
-90
-120
-150
650 680 710 740

high power

770

800

fs-optimized silver AOI = 0°

830

860

890

920

wavelength [nm]Figure 4: Group delay dispersion (GDD) of standard and high power
dielectric mirrors and fs-optimized silver mirrors

56

950

Ultrafast Laser Optics
Components for the Second Harmonic of the Ti:Sapphire Laser (300 – 600 nm)

Components for the Second Harmonic of theTi:Sapphire Laser (300 – 600 nm)
Dual Wavelength Mirrors for AOI = 0°
The second harmonic of the Ti:Sapphire laser provides fs-pulses in the NUV and VIS spectral range. This aspect offers a variety of applications in spectroscopy and materials science. Optics for these special applications must be optimized for both high reflectance and low
dispersion. Negative dispersion mirrors for pulse compression are of interest as well.

Special Features• High reflectance (R > 99.9 %)• Center wavelength and bandwidth according to customer specifications• Spectral tolerance ± 1 %• Prototype production according to customer specifications• In-house design calculation and measurement capabilities
R
100
90
80
70
60
50
40
30
20
10
0

R (99 – 100 %)AOI = 0°b

GDD [fs2]

R [%]

a

300

400

500

600

700

800

900

1000

wavelength [nm]AOI = 0°
150
120
90
60
30
0
-30
-60
-90
-120
-150

360

380

400

420

440

460

wavelength [nm]c

AOI = 0°180

GDD [fs2]

120
60
0
-60
-120
-180

700

750

800
wavelength [nm]

850

900

Figure 1: Reflectance and GDD spectra of a fs-optimized dual wavelength
mirror for
400 nm + 800 nm at AOI = 0°a) Reflectance vs. wavelengthb) GDD vs. wavelength (second harmonic)c) GDD vs. wavelength (fundamental)

57

Ultrafast Laser Optics
Components for the Second Harmonic of the Ti:Sapphire Laser (300 – 600 nm)

Dual Wavelength Turning Mirrors for AOI = 45°
Rs
100
90
80
70
60
50
40
30
20
10
0
350

Rs (99 – 100 %)Rp

Rp (99 – 100 %) AOI = 45°bs-pol.

p-pol.

AOI = 45°

420

440

460

180
120
60

GDD [fs2]

R [%]

a

0
-60
-120

450

550

650

750

850

950

-180

1050

360

380

400

wavelength [nm]cwavelength [nm]s-pol.

p-pol.

AOI = 45°180

GDD [fs2]

120
60
0
-60
-120
-180

700

750

800

850

900

950

wavelength [nm]Figure 2: Reflectance and GDD spectra of a fs-optimized dual wavelength
turning mirror for 400 nm + 800 nm at AOI = 45°a) Reflectance vs. wavelengthb) GDD vs. wavelength (second harmonic)c) GDD vs. wavelength (fundamental)

Separators for the Second Harmonic from the Fundamental for AOI = 45°
Rs
100
90
80
70
60
50
40
30
20
10
0

Rp

AOI = 45°bs-pol.

p-pol.

120
60
0
-60
-120
300

400

500

600

700

800

900

-180
340

360

380

wavelength [nm]

400

420

440

wavelength [nm]Figure 3: Reflectance and GDD spectra of a separator HRs,p (45°, 400 nm) > 99.9 % + Rs,p (45°, 800 nm) < 2 %a) Reflectance vs. wavelengthb) GDD vs. wavelength• Reflectance R > 99.9 % for s- and p-polarization in the reflectance band
• Transmittance T > 95 % for s- and p-polarization in the transmittance band
• These components work for p- and s- polarization, but performance can be optimized if the polarization is clearly specified

58

AOI = 45°180

GDD [fs2]

R [%]

a

460

Ultrafast Laser Optics
Components for the Second Harmonic of the Ti:Sapphire Laser (300 – 600 nm)

Rs
100
90
80
70
60
50
40
30
20
10
0

Rs (99 – 100 %)Rp

Rp (99 – 100 %) AOI = 45°bp-pol.

AOI = 45°50
0
GDD [fs2]

R [%]

a

-50
-100
-150
-200

300

400

500

600

700

800

900

-250
700

1000

750

800

wavelength [nm]

850

900

wavelength [nm]Figure 4: Reflectance and GDD spectra of a separator HRp (45°, 800 nm) > 99.9 % + Rp (45°, 400 nm) < 2 % + Rs (45°, 400 nm) < 10 %a) Reflectance vs. wavelengthb) GDD vs. wavelength• Bandwidth of the 800 nm reflectance band > 200 nm for p-polarization• All separators exhibit |GDD| < 20 fs² in the transmittance band

Negative Dispersion Mirror Pair for the 400 nm Spectral Range at AOI = 0°
mirror A
100
99
98
97
96
95
94
93
92
91
90
300

mirror B

AOI = 0°b

GDD [fs2]

R [%]

a

340

380

420

wavelength [nm]

460

500

mirror A
50
40
30
20
10
0
-10
-20
-30
-40
-50

360

380

400

mirror B

420

average

440

AOI = 0°460

wavelength [nm]Figure 5: Reflectance and GDD spectra of a negative dispersion mirror pair for 350 – 480 nm with an average GDD varying from -30 fs² at 350 nm to 0 fs² at
480 nm (TOD optimized)a) Reflectance vs. wavelengthb) GDD vs. wavelength59

Ultrafast Laser Optics
Components for the Third Harmonic of the Ti:Sapphire Laser (250 – 400 nm)

Components for the Third Harmonic of the Ti:Sapphire Laser(250 – 400 nm)
Dual Wavelength Turning Mirrors for AOI = 45°
Rs
100
99
98
97
96
95
94
93
92
91
90

Rp

AOI = 45°bs-pol.

p-pol.

AOI = 45°

370

410

450

p-pol.

AOI = 45°

180
120
GDD [fs2]

R [%]

a

60
0
-60
-120

250 270

290

310

330

350

370

390

410

430

-180
250

450

290

330

wavelength [nm]wavelength [nm]Figure 1: Reflectance and GDD spectra of a fs-optimized dual wavelength turning mirror for 270 nm and 405 nma) Reflectance vs. wavelengthb) GDD vs. wavelength

Triple Wavelength Turning Mirrors for AOI = 45°
Rs
100
99
98
97
96
95
94
93
92
91
90

Rp

AOI = 45°bs-pol.
360
240

GDD [fs2]

R [%]

a

120
0
-120
-240

200

300

400

500

600

700

800

-360

900

250

265

280 350

wavelength [nm]

400

450

700

800

900

wavelength [nm]Figure 2: Reflectance and GDD spectra of a fs-optimized turning mirror for the 266 nm, 400 nm and 800 nm wavelength regionsa) Reflectance vs. wavelengthb) GDD vs. wavelength

Please note that this triple wavelength turning mirror exhibits |GDD| < 50 fs² in all three wavelength regions of interest.

Separators for the Third Harmonic from the Second Harmonic and the Fundamental Wave for AOI = 45°
Rs
100
90
80
70
60
50
40
30
20
10
0
200

Rp

AOI = 45°b

GDD [fs2]

R [%]

a

300

400

500

600

700

800

900

s-pol.
100
80
60
40
20
0
-20
-40
-60
-80
-100

240

250

wavelength [nm]

260

270

280

p-pol.

290

AOI = 45°300

wavelength [nm]Figure 3: Reflectance and GDD spectra of a standard separator reflecting the third harmonic and transmitting the second harmonic and the fundamentala) Reflectance vs. wavelengthb) GDD vs. wavelength

For the bandwidth of the reflectance and low-GDD ranges, please see table 1 on page 63.

60

310

Ultrafast Laser Optics
Components for the Third Harmonic of the Ti:Sapphire Laser (250 – 400 nm)

Rs
100
90
80
70
60
50
40
30
20
10
0
200

Rp

AOI = 45°bs-pol.

AOI = 45°

330

350

180
120
60

GDD [fs2]

R [%]

a

0
-60
-120

300

400

500

600

700

800

900

-180
210

1000

230

250

wavelength [nm]

270

290

310

370

wavelength [nm]Figure 4: Reflectance and GDD spectra of a broadband separator with high reflectance for s-polarized light throughout the wavelength range of the third
harmonic of the Ti:Sapphire laser and high transmittance for p-polarized light in the VIS and NIR:
HRs (45°, 250 – 330 nm) > 95 % + Rp (45°, 440 – 1000 nm) < 3 %a) Reflectance vs. wavelengthb) GDD-Rs vs. wavelength

Negative Dispersion Mirror Pair for AOI = 0°
mirror A
100
99
98
97
96
95
94
93
92
91
90

mirror B

AOI = 0°b

GDD [fs2]

R [%]

a

240

300

360

420

mirror A
50
40
30
20
10
0
-10
-20
-30
-40
-50
240

wavelength [nm]

260

280

300

mirror B

320

average

340

360

AOI = 0°380

400

wavelength [nm]Figure 5: Reflectance and GDD spectra of a broadband negative dispersion mirror pair
HR (0°, 275 – 400 nm) > 99 % with an average GDD of ≈ -10 fs² per bouncea) Reflectance vs. wavelengthb) GDD vs. wavelength61

Ultrafast Laser Optics
Components for the Higher Harmonics of the Ti:Sapphire Laser (140 – 250 nm)

Components for the Higher Harmonics of theTi:Sapphire Laser (140 – 250 nm)
The fourth, fifth and sixth harmonics of the Ti:Sapphire laser provide fs-pulses in the DUV/VUV range. These harmonics offer a variety of
applications in spectroscopy as well as in materials science. Optics for these very special applications must be optimized for high reflectanceand low dispersion. Mirrors and separators for the wavelength range 125 – 215 nm consist of fluoride layer systems on CaF2 substrates
while components for longer wavelengths can be made of oxides. For mirrors, LAYERTEC recommends substrates with a thickness of 3 mm
or 6.35 mm to achieve good flatness values. For special separators, LAYERTEC offers substrates of Fused Silica or calcium fluoride as thinas 1 mm or 0.5 mm.

Turning Mirrors and Separators for the Fourth Harmonic at AOI = 45°
Measurement
100
98
96
94
92
90
88
86
84
82
80

Rs

Rp

Ru

AOI = 45°

b

R [%]

R [%]

a

180

190

200

210

220

Rs
100
90
80
70
60
50
40
30
20
10
0
160

260

360

wavelength [nm]

c

460

560

660

Rp

760

AOI = 45°

860

960

wavelength [nm]s-pol.

p-pol.

AOI = 45°180

GDD [fs2]

120
60
0
-60
-120
-180
180

185

190

195

200

205

210

215

220

wavelength [nm]Figure 1: Reflectance and GDD spectra of a separator for the fourthharmonic from the longer wavelength harmonics and the fundamental wave (AOI = 45°)a) Reflectance vs. wavelength (measured)b) Reflectance vs. wavelength (calculated)c) GDD vs. wavelength (calculated)

Components for the Fifth Harmonic at AOI = 45°
Measurement
100
98
96
94
92
90
88
86
84
82
80

Rs

Rp

Ru

AOI = 45°s-pol.

p-pol.

AOI = 45°

180
120
60
0
-60
-120
145

150

155

160

165

170

175

wavelength [nm]Figure 2: Reflectance and GDD spectra of a turning mirror for 160 nm (AOI = 45°)a) Reflectance vs. wavelength (measured)b) GDD vs. wavelength (calculated)

62b

GDD [fs2]

R [%]

a

-180
145

150

155

160

165

wavelength [nm]

170

175

180

Ultrafast Laser Optics
Components for the Higher Harmonics of the Ti:Sapphire Laser (140 – 250 nm)

Components for the Sixth Harmonic at AOI = 45°
Measurement
100
90
80
70
60
50
40
30
20
10
0

Ru

AOI = 45°bs-pol.

p-pol.

AOI = 45°

180
120
GDD [fs2]

R [%]

a

60
0
-60
-120

115

125

135

145

155

165

-180

120

125

130

wavelength [nm]

135

140

145

150

wavelength [nm]Figure 3: Reflectance and GDD spectra of a turning mirror for 133 nm (AOI = 45°)a) Reflectance vs. wavelength (measured for unpolarized light)b) GDD vs. wavelength (calculated)

Bandwidth of the Reflectance and Low-GDD Range of Standard Components• The coatings described on page 60 ff. can be used to achieve center wavelengths as given in the following table. Different coating
materials are used for different wavelength ranges• All coatings are optimized for broad reflection bands, high reflectance and low GDDTable 1: Bandwidth of the reflectance and low-GDD range of standard components

Component

Wavelength Range

P-Polarization (|GDD| < 20 fs²)

S-Polarization (|GDD| < 20 fs²)

Turning mirror or separator 3 harmonic

250 nm – 330 nm

30 nm (R > 99 %)50 nm (R > 99 %)Dual wavelength turning mirror

250 nm – 330 nm
370 nm – 500 nm

15 nm (R > 99 %)34 nm (R > 99 %)26 nm (R > 99 %)72 nm (R > 99 %)Turning mirror or separator 4th harmonic

180 nm – 250 nm

5 nm (R > 93 %)15 nm (R > 97 %)Turning mirror or separator 5 harmonic

140 nm – 180 nm

4 nm (R > 90 %)Turning mirror or separator 6th harmonic

125 nm – 140 nmrdth

12 nm (R > 97 %)8 nm (R > 85 % unpolarized)

63Ultrafast Laser Optics
Gires-Tournois-Interferometer (GTI) Mirrors (600 – 1600 nm)

Gires-Tournois-Interferometer (GTI) Mirrors (600 – 1600 nm)
Gires-Tournois-Interferometer (GTI) mirrors are used for pulse compression in short pulse lasers such as Yb:YAG- or Yb:KGW-lasers.
LAYERTEC also offers GTI mirrors for the Ti:Sapphire wavelength range and for other ultrafast lasers in the NIR spectral range. Compared
to prism compressors, GTI mirrors reduce the intra cavity losses resulting in higher output power of the laser.

Special Features• Very high reflectance• Center wavelength, bandwidth and GDD according to customer specifications• Please note that bandwidth and GDD are closely connected. A high value of negative GDD results in a very narrow bandwidth• Spectral tolerance ± 1 %• In-house design calculation and measurement capabilities (GDD 250 – 1700 nm, reflectance measurement by CRD 210 – 1800 nm)
Table 1: LIDT Info

LIDT

Wavelength

Pulse Duration≈ 0.1 J/cm²

800 nm

150 fs≈ 225 mJ/cm²

1030 nm

44 fs

Repetition Rate

Pulses at each Site

Beam Diameter

1 KHz

100 000-on-1

1/e² ≈ 750 µm

Measurements at
Laser Zentrum Hannover
DESY Hamburg 2021

GTI-Mirrors for Yb:YAG and Yb:KGW-Lasers-500 fs2-1300 fs2

AOI = 0°-2500 fs2
0

-400

-2500

-10000 fs2

AOI = 0°

1040

1050

1060

-7500

-10000

-1600
-2000
1010

-5000 fs2

-5000

-800

-1200

-12500
1020

1030

1040

1050

1060

wavelength [nm]Figure 1: GDD spectra of GTI-mirrors for 1040 nm with different GDD Valuesa) -500 fs², -1300 fs²b) -2500 fs², -5000 fs², -10 000 fs²• Typical reflectance values depending on dispersion:-500 fs²: R ≥ 99.99 %-1300 fs²: R ≥ 99.98 %-2500 fs²: R ≥ 99.97 %-5000 fs²: R ≥ 99.95 %-10 000 fs²: R ≥ 99.95 %

64

b

0

GDD [fs2]

GDD [fs2]a-15000
1010

1020

1030

wavelength [nm]Ultrafast Laser Optics
Gires-Tournois-Interferometer (GTI) Mirrors (600 – 1600 nm)

AOI = 0°AOI = 0°1200
1000
GDD [fs2]

GDD [fs2]

1000
800
600
400
200
0
-200
-400
-600
-800
-1000
980

800
600
400
200

1000

1020

1040

1060

0
1010

1080

1030

wavelength [nm]

1050

1070

1090

wavelength [nm]Figure 2: GTI mirror with nearly constant TOD

Figure 3: GTI mirror with positive GDD

AOI = 0°0

GDD [fs2]

-200
-400
-600
-800
-1000
1000

1010

1020

1030

1040

1050

1060

wavelength [nm]Figure 4: GDD spectrum of a rear side GTI mirror with
GDD (0° – 10°, 1030 nm) ≈ -700 fs²

The mirror is irradiated through the substrate which has an AR coating on the front side. Rear side GTI mirrors are insensitive against surface
contaminations which sometimes distort the GDD spectrum of common front side GTI mirrors.

Optical Losses of GTI-Mirrors
without absorption losses

with typical absorption losses AOI = 0°

Measurement

99.98

99.98

99.96

99.96

R [%]

100.00R [%]100.00

99.94

99.94

99.92

99.92

99.90
1010

1020

1030

1040

1050

1060

1070

wavelength [nm]Figure 5: Calculated reflectance spectra of a GTI mirror without absorption
losses (black) and with typical absorption losses (grey)

99.90
1020

AOI = 0°

1030

1040

1050

1060

wavelength [nm]Figure 6: Measured reflectance spectrum of a GTI mirror (design as calculated in figure 5)

GTI mirrors of LAYERTEC show high reflectance values (e.g. R > 99.98 % at 1030 nm). The reflectance can be measured exactly by CRD.
The high reflectance proves that the absorption losses in the GTI mirrors are very small. This also results in very small thermal lensing insidethese GTI mirrors if they are used in high power lasers.

65

Ultrafast Laser Optics
Gires-Tournois-Interferometer (GTI) Mirrors (600 – 1600 nm)

Coating Homogenity and Reproducibility of GTI-Mirrors
Figure 8 and figure 9 show that all GTI mirrors which were produced in these batches meet the specifications given in figure 7. Comparing
mirrors from two batches the variation within a batch and between batches are much smaller than what is allowed by the specifications.
The excellent reproduction of complex coating designs is the basis for the use of GTI mirrors in industrial short pulse lasers.
AOI = 6°

Measurement

-500

-500

-600

-600
-700
GDD [fs2]

GDD [fs2]

-700
-800
-900

-800
-900

-1000

-1000

-1100

-1100

-1200
1010

1020

1030

1040

1050

1060

1070

wavelength [nm]Measurement

AOI = 6°-500
-600
GDD [fs2]

-700
-800
-900

-1000
-1100
-1200
1010

1020

1030

1040

-1200
1010

1020

1030

1040

1050

1060

1070

wavelength [nm]Figure 7: Calculated GDD spectrum of a GTI mirror: GDD-R (6°, 1020 –1060 nm) ≈ -1000 ± 200 fs²

1050

1060

1070

wavelength [nm]Figure 9: Measured GDD spectra of 6 GTI mirrors which were coated in asecond batch according to the design of figure 7

66

AOI = 6°

Figure 8: Measured GDD spectra of 6 GTI mirrors which were coated in
the same batch according to the design of figure 7

Ultrafast Laser Optics
Optics for Ultrafast Lasers in the Wavelength Range of 1000 – 1600 nm

Optics for Ultrafast Lasers in the Wavelength Range of1000 – 1600 nm
Although Ti:Sapphire lasers are currently the most important ultrafast lasers, many applications require ultrafast pulses at considerably
longer wavelengths. Several lasers emitting light between 1100 nm and 1600 nm have been developed, such as the Cr:Forsterite laser(1150 – 1350 nm) or the Er:Fiber laser (1550 nm). Some examples of coatings such as negative dispersion mirrors and mirror pairs for thesewavelength ranges are presented.

Special Features• Very high reflectance of the mirrors (R > 99.8 % … R > 99.99 % depending on the design)• Center wavelength, bandwidth, GDD and TOD according to customer specifications• Spectral tolerance ± 1 %• In-house design calculation and measurement capabilities (GDD 250 – 1700 nm, reflectance 210 – 1800 nm)

Negative Dispersion Laser and Pump Mirrors for AOI = 0°
a

b

R [%]

GDD [fs2]

AOI = 0°

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1050

1100

1150

1200

1250

1300

1350

1400

1450

AOI = 0°
150
120
90
60
30
0
-30
-60
-90
-120
-150
1100

1150

1200

wavelength [nm]

1250

1300

1350

1400

1450

wavelength [nm]Figure 1: Reflectance and GDD spectra of a negative dispersion laser mirror (GDD ≈ -60 fs² for 1200 – 1370 nm)a) Reflectance vs. wavelengthb) GDD vs. wavelength
R
100
90
80
70
60
50
40
30
20
10
0
1000

R (99 – 100 %)AOI = 0°b

GDD [fs2]

R [%]

a

1150

1300

1450

1600

wavelength [nm]AOI = 0°
0
-30
-60
-90
-120
-150
-180
-210
-240
-270
-300
1050

1100

1150

1200

1250

1300

1350

1400

1450

wavelength [nm]Figure 2: Reflectance and GDD spectra of a negative dispersion pump mirror:
HR (0°, 1180 – 1380 nm) > 99.8 % + R (0°, 1020 – 1070 nm) < 5 %,GDD-R (0°, 1180 – 1380 nm) ≈ -150 fs²a) Reflectance vs. wavelengthb) GDD vs. wavelength67

Ultrafast Laser Optics
Optics for Ultrafast Lasers in the Wavelength Range of 1000 – 1600 nm

GTI-Mirrors for AOI = 0°a-200 fs2-350 fs2-500 fs2

AOI = 0°b-200 fs2-350 fs2-500 fs2

AOI = 0°

1520

1560

1600

0

GDD [fs2]

-100

R [%]

100.0
99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

-200
-300
-400
-500

1300

1400

1500

1600

1700

-600
1400

1800

1440

1480

wavelength [nm]wavelength [nm]Figure 3: Reflectance and GDD spectra of GTI mirrors for 1500 nm with different GDD valuesa) Reflectance vs. wavelengthb) GDD vs. wavelength

Broadband Negative Dispersion Mirror Pairs for AOI = 0°amirror A

mirror B

AOI = 0°b

100

GDD [fs2]

R [%]

99
98
97
96
95

850

950

1050

1150

1250

1350

wavelength [nm]

1450

1550

1650

mirror A
500
400
300
200
100
0
-100
-200
-300
-400
-500

950

1050

1150

1250

mirror B

1350

average

1450

AOI = 0°

1550

1650

wavelength [nm]Figure 4: Reflectance and GDD spectra of a broadband negative dispersion mirror pair; single mirrors with R > 99.7 % (mirror A) and R > 99.85 % (mirror B)a) Reflectance vs. wavelengthb) GDD vs. wavelength

Specially designed mirror pairs show a very smooth average GDD spectrum, although the single broadband mirrors exhibit strong GDD
oscillations. Pump mirror pairs (i.e. mirror pairs with one mirror showing high transmittance at the pump wavelength of the respective lasertype) are also available.

68Ultrafast Laser Optics
Optics for Ultrafast Lasers in the Wavelength Range of 1000 – 1600 nm

Broadband Negative Dispersion Turning Mirrors for AOI = 45°a

AOI = 45°

b

R [%]

GDD [fs2]

Rp

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

1000

1100

1200

1300

1400

1500

1600

p-pol.
500
400
300
200
100
0
-100
-200
-300
-400
-500
1000

1100

1200

wavelength [nm]

1300

1400

AOI = 45°

1500

1600

wavelength [nm]Figure 5: Reflectance and GDD spectra of a broadband negative dispersion mirrorsa) Reflectance vs. wavelengthb) GDD vs. wavelength

Please note the large bandwidth of this mirror. In contrast, low dispersion turning mirrors are available with bandwidths of about 200 nm
for p-polarization and about 400 nm for s-polarization in this wavelength range.
p-pol
100
90
80
70
60
50
40
30
20
10
0
400

AOI = 45°

b

R [%]

R [%]

a

500

600

700

800

900

1000

1100

1200

s-pol
100
99
98
97
96
95
94
93
92
91
90

1000 1100

1200

wavelength [nm]

c

1400

1500

1600

1700

1800

wavelength [nm]p-pol

AOI = 45°

d
2000
1600
1200
800
400
0
-400
-800
-1200
-1600
-2000

s-pol

AOI = 45°

GDD [fs2]

GDD [fs2]

2000
1600
1200
800
400
0
-400
-800
-1200
-1600
-2000
400

1300

AOI = 45°

500

600

700

800

900

1000

1100

1200

1000 1100

wavelength [nm]

1200

1300

1400

1500

1600

1700

1800

wavelength [nm]Figure 6: Reflectance and GDD spectra of a beam combiner:
HRs (45°, 1100 – 1700 nm) > 99.5 % + Rp (45°, 450 – 900 nm) < 15% (average Rp < 10 %)|GDD-Rs (45°,1100 – 1700 nm)| < 750 fs² + |GDD-Tp (45°,450 – 950 nm)| < 300 fs²a) Reflectance p-pol. vs. wavelengthb) Reflectance s-pol. vs. wavelengthc) GDD-Tp (45°) vs. wavelengthd) GDD-Rs (45°) vs. wavelength69

Selected Special Components

Selected Special Components

Chapter Index
Components for Optical Parametric Oscillators (OPO).......71
Cavity Mirrors for AOI = 0°.....................................................71
Pump Mirrors and Separators for AOI = 0°.............................71
Output Couplers.....................................................................72
Beam Splitters for AOI = 45°..................................................73
Special Output Couplers for AOI = 0°.....................................73
Turning Mirrors and Separators for AOI = 45°.........................73
Ultra Broadband Components for AOI = 45°..........................74
Edge Filters for AOI = 45°.......................................................75
Coatings on Nonlinear Optical Crystals AOI = 0°.....................75
Broadband and Scanning Mirrors (300 – 2500 nm)...........76
Broadband Mirrors.................................................................76
Scanning Mirrors....................................................................77
Filters for Laser Applications (260 – 2500 nm)..................78
Calibration Filters (300 – 5000 nm).........................................78
Spectral Graduated Filters (300 – 4000 nm)............................78
Steep Edge Filters...................................................................78
Narrowband Reflectance Filters..............................................79
Dual Wavelength Filters with Broad Blocking Range...............79
Thin Film Polarizers...........................................................80
Standard Thin Film Polarizers..................................................81
Special Thin Film Polarizers.....................................................81
Low Loss Optical Components (340 – 3000 nm)................82
HR Mirrors..............................................................................82
Coatings on Crystal Optics (340 – 3000 nm)......................84
Coatings on Doped Laser Crystals...........................................85
Coatings on Nonlinear Optical Crystals...................................8570

Selected Special Components
Components for Optical Parametric Oscillators (OPO)

Components for Optical Parametric Oscillators (OPO)
Mirrors for OPOs are optimized for separation of the pump laser, signal and idler wavelengths. This application requires a broad reflectance band for the signal wavelength and a wide range of high transmittance for the idler and pump wavelengths. Moreover, most of
the optics show smooth group delay (GD) and group delay dispersion (GDD) spectra. Thus, wide tuning ranges for the signal and the idler
wavelengths can be achieved. This enables the operation of OPOs with fs-pulses. Broadband output couplers are also available. Center
wavelength and tuning range can be adjusted according to customer specifications. All OPO coatings are produced by magnetron sputtering. This process guarantees that the optical parameters are environmentally stable, because the coatings are compact, free of waterand adhere strongly to the substrate in spite of the extreme coating thickness of 20 – 30 μm. This makes sputtered OPO coatings ideal for
application in harsh environments.

Cavity Mirrors for AOI = 0°a

AOI = 0°b

GDD [fs2]

GD [fs]750

GDD [fs2]

500

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
900

250
0
-250
-500

1000

1100

1200

1300

1400

1500

1600

-750
900

1700

1000

1100

wavelength [nm]

1200

1300

1400

1500

1600

1700

wavelength [nm]Figure 1: Reflectance, GD and GDD spectra of a broadband HR mirror for the signal wavelength: HR (0°, 1000 – 1600 nm) > 99.9 %a) Reflectance vs. wavelengthb) GDD vs. wavelength
AOI = 0°
100
95
90
85
80
75
70
65
60
55
50
1300

b

GDD [fs2]

GD [fs]
2000
1500
1000

GD, GDD

R [%]

a

500
0
-500

-1000
-1500
2100

2900

3700

4500

5300

-2000
1300

2100

wavelength [nm]

2900

3700

4500

5300

wavelength [nm]Figure 2: Reflectance, GD and GDD spectra of a dual HR mirror for the signal and idler wavelengths:
HR (0°, 1400 – 1800 nm) > 96 % + HR (0°, 2900 – 4900 nm) > 93 %a) Reflectance vs. wavelengthb) GD and GDD vs. wavelength

Pump Mirrors and Separators for AOI = 0°
R
100
90
80
70
60
50
40
30
20
10
0

R (99 – 100 %)AOI = 0°

b

4600

1000
800
600
400
200
0
-200
-400
-600
-800
-1000
850

GD [fs]GDD [fs2]

GD, GDD

R [%]

a

600

1400

2200

3000

3800

wavelength [nm]

950

1050

1150

1250

1350

1450

1550

1650

wavelength [nm]Figure 3: Reflectance, GD and GDD spectra of an OPO pump mirrora) Reflectance vs. wavelengthb) GD and GDD vs. wavelength

This type of mirror separates the pump and signal wavelengths while suppressing the idler wavelength:
R (0°, 700 – 850 nm) < 10 % + HR (0°, 900 – 1600 nm) > 99.8 % + R (0°, 1800 – 5000 nm) < 60 %.

71

Selected Special Components
Components for Optical Parametric Oscillators (OPO)

R
100
90
80
70
60
50
40
30
20
10
0
1000

R (99 – 100 %)AOI = 0°b

GDD [fs2]

GD [fs]
2000
1500
1000

GD, GDD

R [%]

a

500
0
-500

-1000
-1500
1400

1800

2200

2600

3000

-2000
1100

1200

1300

wavelength [nm]

1400

1500

1600

wavelength [nm]Figure 4: Reflectance, GD and GDD spectra of a separator for the signal and idler wavelengthsa) Reflectance vs. wavelengthb) GD and GDD vs. wavelength• Edge filters separating signal and idler wavelengths can be used as broadband out-coupling mirrors for the idler:
HR (0°, 1100 – 1600 nm) > 99.8 % + R (0°, 1730 – 2900 nm) < 10 %• These filters can also be provided with a band of high reflectance or high transmittance for the pump wavelengths or for the second
harmonic of the signal wavelengths• LAYERTEC recommends undoped YAG or sapphire as substrate material if high transmittance for the idler wavelengths is required(see also page 138 f. for transmittance curves)
R (99 – 100 %)AOI = 0°AOI = 0°

R [%]

R [%]

R
100
90
80
70
60
50
40
30
20
10
0
1000

1800

2600

3400

4200

5000

100
90
80
70
60
50
40
30
20
10
0

1500

1900

2300

wavelength [nm]

2700

3100

3500

wavelength [nm]Figure 5: Reflectance spectrum of a broadband mirror for the NIR:
HR (0°, 2300 – 4000 nm) > 99 %Figure 6: Reflectance spectrum of a separator for the signal and idler
wavelengths:
HR (0°, 2050 – 3500 nm) > 99 % + R (0°, 1600 – 1930 nm)<5%Output Couplers
R = 91 % ±2 %
100
90
80
70
60
50
40
30
20
10
0

R = 75 % ±4 %AOI = 0°

b
1000
800
600
400
200
0
-200
-400
-600
-800
-1000
800

reflected beamtransmitted beam

GDD [fs2]

R [%]

a

800

900

1000

1100

1200

1300

wavelength [nm]

1400

1500

1600 1700

900

1000

1100

1200

1300

1400

1500

1600 1700

wavelength [nm]Figure 7: Reflectance and GDD spectra of different broadband output couplers for the signal wavelength range.
a) Reflectance vs. wavelengthb) GDD vs. wavelength (The spectra shown are calculated for the 75 % output coupler, but the spectra for other reflectance values are very similar.)

The reflectance of output couplers and beam splitters can be adjusted according to customer specifications.

72Selected Special Components
Components for Optical Parametric Oscillators (OPO)

Beam Splitters for AOI = 45°
Rp
100
90
80
70
60
50
40
30
20
10
0

AOI = 45°b

GDD [fs2]

R [%]

a

1100

1300

1500

1700

1900

2100

2300

2500

reflected beam p-pol.
200
160
120
80
40
0
-40
-80
-120
-160
-200
1100

1300

1500

wavelength [nm]1700transmitted beam p-pol.

1900

2100

2300

2500

wavelength [nm]Figure 8: Reflectance and GDD spectra of a broadband beam splitter for p-polarized signal and idler radiation: PRp (45°, 1100 – 2400 nm) = 50 % ± 5 %a) Reflectance vs. wavelengthb) GDD vs. wavelength

Special Output Couplers for AOI = 0°
AOI = 0°

R [%]

R [%]

AOI = 0°
100
90
80
70
60
50
40
30
20
10
0
1300

1900

2500

3100

3700

4300

100
90
80
70
60
50
40
30
20
10
0
800

1600

wavelength [nm]

2400

3200

4000

4800

wavelength [nm]Figure 9: Reflectance spectrum of a special output coupler:PR (0°, 2000 – 3150 nm) = 90 % ± 3 %+ R (0°, 1400 – 1700 nm) < 3 %Figure 10: Reflectance spectrum of a special output coupler:PR (0°, 1350 – 2000 nm) = 98 % ± 0.5 %+ R (0°, 1000 – 1100 nm) < 3 %+ R (0°, 2200 – 5000 nm) < 20 %The output couplers for the signal wavelengths figure 9 can suppress the idler and vice versa figure 10. These output couplers may also
have a pump window.

Turning Mirrors and Separators for AOI = 45°
a

Rs

Rp

AOI = 45°b

GDD-Rp [fs2]GD-Rp [fs]400
200

GD, GDD

0

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1200

-200
-400
-600
-800

1400

1600

1800

2000

2200

2400

-1000
1400

1500

wavelength [nm]

1600

1700

1800

1900

2000

2100

2200

wavelength [nm]Figure 11: Reflectance, GD and GDD spectra of a turning mirror HRp (45°, 1450 – 2000 nm) > 99.8 %a) Reflectance vs. wavelengthb) GD-Rp and GDD-Rp vs. wavelength

Turning mirrors and separators for pump, signal and idler are key components of OPOs. The spectral position of the reflectance andtransmittance bands can be adjusted according to customer specifications. Please note that GD and GDD can only be optimized for s- or
p-polarization while the reflectance is usually very high for both polarizations.

73Selected Special Components
Components for Optical Parametric Oscillators (OPO)

Rp
Rp (99 – 100 %)AOI = 45°
100
90
80
70
60
50
40
30
20
10
0
800 1200 1600 2000 2400 2800 3200 3600 4000 4400 4800b

GDD-Rp [fs2]GD-Rp [fs]
400
200
0

GD, GDD

R [%]

a

-200
-400
-600
-800

-1000
1300

1400

1500

1600

wavelength [nm]

1700

1800

1900

2000

2100

wavelength [nm]Figure 12: Reflectance, GD and GDD spectra of a separator for signal and idlera) Reflectance vs. wavelengthb) GD and GDD vs. wavelength

A broad reflectance band for the signal is combined with a broad transmittance band for the idler:
HRp (45°, 1450 – 2000 nm) > 99.8 % + Rp (45°, 2350 – 4000 nm) < 10 %.
Rs
100
90
80
70
60
50
40
30
20
10
0

Rp

AOI = 45°b

GD, GDD

R [%]

a

450

750

1050

1350

1650

1950

GD-Rp [fs]
100
80
60
40
20
0
-20
-40
-60
-80
-100

700

wavelength [nm]

750

800

850
wavelength [nm]Figure 13: Reflectance, GD and GDD spectra of a separator for the signal and idler with high transmittance for the pump radiationa) Reflectance vs. wavelengthb) GD and GDD vs. wavelength

This separator can be used to couple the pump radiation into the resonator:
HRs (45°, 770 – 930 nm) > 99.8 % + Rp (45°, 510 – 550 nm) < 1 % + Rp (45°, 1160 – 1900 nm) < 10 %.

Ultra Broadband Components for AOI = 45°

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0

800

1800

2800

3800

Rp

4800

AOI = 45°5800

wavelength [nm]Figure 14: Reflectance spectrum of an ultra broadband separator for signal and idler wavelengths:
HRu (45°, 1000 – 2500 nm) > 98 %+ Ru (45°, 4400 – 5000 nm) < 5 %

74

900

GDD-Rp [fs2]

950

1000

Selected Special Components
Components for Optical Parametric Oscillators (OPO)

Edge Filters for AOI = 45°
AOI = 45°

Rs

R [%]

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0

900

1400

1900

2400

2900

100
90
80
70
60
50
40
30
20
10
0

900

1700

2500

wavelength [nm]

3300

Rp

AOI = 45°

4100

4900

wavelength [nm]Figure 15: Reflectance spectrum of an edge filter for the idler and signal
wavelength range with high transmittance for the pump wavelength:
HRs (45°, 2150 – 2700 nm) > 99.9 %+ Rs (45°, 2000 – 2070 nm) < 10 % + Rs (45°, 1064 nm) < 1 %Figure 16: Reflectance spectrum of a broadband edge filter for the idler
wavelength range with high transmittance for the pump wavelength:
HRs (45°, 3300 – 4200 nm) > 99.9 %+ Rs (45°, 4500 – 4900 nm) < 6 % + Rs,p (45°, 1064 nm) < 5 %Coatings on Nonlinear Optical Crystals AOI = 0°
AOI = 0°

R [%]

R [%]

AOI = 0°
10
9
8
7
6
5
4
3
2
1
0
900

1400

1900

2400

2900

10
9
8
7
6
5
4
3
2
1
0
1850

2350

2850

wavelength [nm]

3350

3850

4350

Figure 17: Reflectance spectrum of an AR coating on lithium niobate:
R (0°, 1064 nm) < 0.5 % + R (0°, 1750 – 2750 nm) < 1 %Figure 18: Reflectance spectrum of an AR coating on lithium niobate:
R (0°, 1910 – 2030 nm) < 0.5 % + R (0°, 3200 – 4200 nm) < 1 %AOI = 0°

R [%]

R [%]

AOI = 0°
10
9
8
7
6
5
4
3
2
1
0
950

1450

1950

2450

2950

4850

wavelength [nm]

3450

3950

wavelength [nm]Figure 19: Reflectance spectrum of an AR coating on lithium niobate:
R (0°, 1064 nm) < 0.5 %+ R (0°, 1420 – 1640 nm) < 0.5 %+ R (0°, 3150 – 3700 nm) < 2 %

4450

100
90
80
70
60
50
40
30
20
10
0

600

1100

1600

2100

2600

3100

3600

wavelength [nm]Figure 20: Reflectance spectrum of a double reflector with two regions ofhigh transmittance on lithium niobate:
HR (0°, 1010 – 1075 + 2750 – 3450 nm) > 99.8 %+ R (0°, 700 – 900 + 1200 – 2400 nm) < 10 %75

Selected Special Components
Broadband and Scanning Mirrors (300 – 2500 nm)

Broadband and Scanning Mirrors (300 – 2500 nm)
LAYERTEC produces broadband and scanning mirrors according to customer specifications. Full dielectric and metal-dielectric coating
designs are available. In the following, examples designed for broad wavelength regions or extremely large ranges of incidence angles arepresented.
Broadband mirrors are widely used to reflect light from lasers that emit in a broad wavelength range like for example Ti:Sapphire lasers, dyelasers, or a combination of different diode lasers. Special mirrors are also available to cover the whole visible spectrum, the near ultraviolet
and considerable parts of the near infrared spectral regions. LAYERTEC recommends such mirrors as universal turning mirrors for nearly
all types of laser diodes.
Broadband mirrors for the NIR range are especially useful for reflecting idler wavelengths of optical parametric oscillators or for special
fs-applications. In combination with Fused Silica as a substrate material, a large blocking range from 2300 to 6000 nm can be achieved.
Other NIR materials such as sapphire and YAG are possible alternatives. These materials can be used for high power applications to improvethe cooling of the optics by the thermal conductivity of the substrate. This may be necessary if the absorption of water (around 2.8 μm) orof the coating material itself leads to an increase in temperature.

Broadband Mirrors
b
100
99
98
97
96
95
94
93
92
91
90

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
450

R [%]

R [%]

a

300

350

400

450

500

550

600

wavelength [nm]

550

650

750

850

950

1050

1150

wavelength [nm]

c

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

1000

1200

1400

1600

1800

wavelength [nm]

76

2000

2200

2400 2600

Figure 1: CRD-measurements R (0 – 10°) of an ultra broadband mirror set
as reference plates for reflection measurementsa) HRu (0 – 10°, 325 – 580 nm) > 99.8 … 99.97 %b) HRu (0 – 10°, 500 – 1050 nm) > 99.95 %c) HRu (0 – 10°, 1020 – 2490 nm) > 99.95 %Selected Special Components
Broadband and Scanning Mirrors (300 – 2500 nm)

Scanning Mirrors
LAYERTEC offers scanning mirrors for high power laser applications and for special demands with respect to wavelength and AOI range.
Scanning mirrors are optimized for high reflectance for one wavelength or a certain wavelength region at a wide range of angles ofincidence. LAYERTEC’s coating technology provides industrial solutions for lightweight scanning mirrors as well as special mirrors with
uncommon sizes up to 600 mm for research with cw and pulsed high power lasers.
AOI = 22°
100
90
80
70
60
50
40
30
20
10
0

AOI = 45°

AOI = 58°

b

R [%]

R [%]

a

625

635

645

655

665

675

100
99
98
97
96
95
94
93
92
91
90

700

800

wavelength [nm]AOI = 22°

AOI = 45°

AOI = 58°

900

1000

1100

wavelength [nm]Figure 2: Reflectance spectra of a silver based scanning mirror with enhanced wavelength range for laser diodes in the NIR:
HRu (22° – 58°, 800 – 1000 nm) > 99 % + Ru (22° – 58°, 630 – 670 nm) > 50 %R [%]AOI = 0°100.00
99.99
99.98
99.97
99.96
99.95
99.94
99.93
99.92
99.91
99.90

0

10

20

30

40

50

60

70

80

90

angle of incidence [°]Figure 3: Reflectance vs. AOI of a wide angle scanning mirror for polarized
Nd:YAG laser radiation: HRs (0° – 90°, 1064 nm) > 99.9 %These mirrors are ideal as scanning mirrors for s-polarized light or to facilitate the production of optical gratings.
AOI = 22°
100
98
96
94
92
90
88
86
84
82
80
600

AOI = 45°

AOI = 58°

650

700

750

800

850

900

950

1000

AOI = 22° p-pol
AOI = 22° s-polb

GDD [fs2]

R [%]

a

150
120
90
60
30
0
-30
-60
-90
-120
-150

700

725

750

wavelength [nm]AOI = 58° p-pol
AOI = 58° s-pol

AOI = 45° p-pol
AOI = 45° s-pol

775

800

825

850

875

900

wavelength [nm]Figure 4: Reflectance and GDD spectra of a scanning mirror for ultrafast laser pulses from a Ti:Sapphire laser:
HRu (22° – 58°, 750 – 850 nm) > 99.5 %, |GDD-Ru (22° – 58°, 750 – 850 nm)| < 20 fs²a) Reflectance vs. wavelengthb) GDD vs. wavelength

The broad low-GDD wavelength range of these mirrors makes it possible to use them in ultrafast laser applications. For more information
or more examples on broadband and scanning mirrors please see page 14 ff. (optics for Ti:Sapphire and diode lasers), page 37 ff. and,especially for scanning mirrors, page 87 f. (silver mirrors).

77

Selected Special Components
Filters for Laser Applications (260 – 2500 nm)

Filters for Laser Applications (260 – 2500 nm)
Calibration Filters (300 – 5000 nm)
T

T [%]

T [%]

T
100
90
80
70
60
50
40
30
20
10
0

450

500

550

600

650

700

750

800

100
90
80
70
60
50
40
30
20
10
0
450

500

550

wavelength [nm]

600

650

700

750

800

wavelength [nm]Figure 1: Transmission spectra of a sputtered multiline filter (VIS) to calibrate CCD-spectrometer (FHWM ≈ 1.5 nm at 546 nm)

Figure 2: Transmission spectra of a sputtered multiline filter (VIS) to calibrate CCD-spectrometer (FHWM ≈ 1 nm at 546 nm)

The number of lines and the spectral range are set according to customer requirements and are supplied with spectral measurement curves.

Spectral Graduated Filters (300 – 4000 nm)
These filters are developed for building spectrometers with inexpensive (smaller) CCD camera chips.

T [%]

T1
100
90
80
70
60
50
40
30
20
10
0

300

400

500

600

700

800

900

T2

1000

T3

1100 1200

wavelength [nm]Figure 3: Small gradient filter

Figure 4: Calculated transmission for three different lateral positions of
AOI = 0°Special Features• Linear variation of the filter wavelength with respect to the lateral position on the filter• Blocking range: 200 to 1300 nm with OD2 to OD4• Filter area < sensor area
simple geometrical adjustment by spectral pixel calibration and/or free positioning

Steep Edge Filters
Ts
100
90
80
70
60
50
40
30
20
10
0

620

630

640

650
wavelength [nm]

78

Tp

Tu

AOI = 22.5°

b

T [%]

T [%]

a

660

670

680

Ts
100
90
80
70
60
50
40
30
20
10
0

500

570

640

Tp

710

wavelength [nm]Figure 5: Transmittance spectra of a steep edge short-wavelength pass filter for use as a combiner for laser diodes at 635 nm and 670 nm
HRu (22.5°, 670 nm) > 99.9 % + Ru (22.5°, 635 nm) < 2 %, rear side AR coated)a) Section around the edge of the blocking bandb) Spectral overview

Tu

780

AOI = 22.5°

850Selected Special Components
Filters for Laser Applications (260 – 2500 nm)

For more information on combiners for diode lasers see page 16. For steep edge filters used as pump mirrors for solid-state lasers basedon Yb-doped materials (e.g. Yb:YAG, Yb:KGW, Yb-doped fibers) see page 18.

Narrowband Reflectance Filters
Filters of this type are ideal for the blocking of a single laser line while preserving a high and relatively constant transmittance over thewhole visible range.

100
90
80
70
60
50
40
30
20
10
0
450

R

AOI = 0°

b

R [%]

R [%]

a

470

490

510

530

550

570

590

610

630

650

100
90
80
70
60
50
40
30
20
10
0
350

R

550

750

950

AOI = 0°1150 1350 1550 1750 1950 2150 2350

wavelength [nm]wavelength [nm]Figure 6: Reflectance spectrum of a narrowband reflectance filter for 550 nm

Special Features• Filters for laser applications require excellent spectral quality and high damage thresholds• Spectral position of cut-on/cut-off wavelengths or reflectance bands according to customer specification• Sizes and shapes: Edge filters can be produced on round or rectangular substrates up to diameters of 38.1 mm (1.5 inch). The
production of miniature size filters (e.g. 3 × 3 mm²) is possible. Narrowband reflectance filters are limited to diameters of 25.4 mm(1 inch).
• Optical parameters are environmentally stable

Dual Wavelength Filters with Broad Blocking Range
AOI = 0°
100
90
80
70
60
50
40
30
20
10
0

750

1000

1250

1500

1750

2000

2250

wavelength [nm]AOI = 0°
100
90
80
70
60
50
40
30
20
10
0

750

1000

1250

1500

1750

2000

2250

wavelength [nm]

c

R [%]

b

R [%]

R [%]

a

AOI = 0°
100
90
80
70
60
50
40
30
20
10
0

750

1000

1250

1500
wavelength [nm]

1750

2000

2250

Figure 7: Reflectance spectra of a dual wavelength filter for 1064 nm
and 1570 nm with a broadband blocking range from the UV to2100 nm. Double side coating reduces the mechanical stress.
Blocking in the UV/VIS is done by a optical filter glass.
a) Front side coatingb) Rear side coatingc) Combination of front and rear side coating

79Selected Special Components
Thin Film Polarizers

Thin Film Polarizers
In order to answer frequently asked questions and to help LAYERTEC’s customers to specify thin film polarizers, definitions of the mostimportant technical terms are given here.
Rs

Rp

AOI = 45°

70

80

30
25

R [%]

20
15
10
ΘB

5
0

0

10

20

30

40

50

60

90

wavelength [nm]transmitted beams,p - polarization

ΘB

ΘB

reflected beams - polarization

al

orm

en

ΘB: Brewster‘s angle

fac

sur

incident beams,p - polarization

Figure 1: Explanation of the terms “s-polarized light” and “p-polarized
light” and reflectance of an uncoated glass surface vs. angle ofincidence for s- and p-polarized lightLight is a transversal wave; the vector of the electric field oscillates perpendicular with respect to the propagation direction of
the light. Natural light (from the sun or from a lamp) is mostly“unpolarized”. This means that the oscillation planes of the electricfield vectors of the single light waves are randomly distributed, but
always transversal with respect to the direction of propagation. In
contrast, the term “linearly polarized light” signifies that there is
only one plane of oscillation. There are different optics which canpolarize light. An example of this would be crystal polarizers which
split light into an unpolarized “ordinary beam” and a polarized “extraordinary beam” or thin film polarizers.
To explain the meaning of the terms “s-polarization” and “p-polarization”, first a reference plane must be determined (see figure1). This plane is spanned by the incident beam and by the surface
normal of the mirror (or polarizer). “S-polarized light” is the partof the light which oscillates perpendicularly to this reference plane(“s” comes from the German word “senkrecht” = perpendicular).
“P-polarized light” is the part which oscillates parallel to the reference plane. Light waves with a plane of oscillation inclined tothese directions can be described as having a p-polarized and ans-polarized part.
The upper part of figure 1 shows the reflectance of an uncoatedglass surface vs. AOI for s- and p-polarized light. The reflectancefor s-polarized light increases with rising angle of incidence. In
contrast, the reflectance of p-polarized light decreases until reaching R = 0 at the “Brewster’s angle”, then increases for angles ofincidence beyond the Brewster’s angle. In principle, the same istrue for dielectric mirrors. Thin film polarizers separate the s-polarized component of the light from the p-polarized component using
the effect that s-polarized light posseses a higher reflectance andbroader reflection band than p-polarized light.

There always is a wavelength range, where Rs is close to 100 % while Rp is close to zero. Special coating designs are used to make thiswavelength range as broad as possible and to maximize the polarization ratio Tp/Ts. Very high values of Tp (> 99.5 %) can be measured very
precisely using a special Cavity Ring-Down set-up. The TFP is inserted into a cavity thus introducing additional losses equal to 100 %-Tp.
Utilizing this method, the most beneficial AOI for each TFP can be determined. Thin film polarizers (TFPs) are key components in a wide
variety of applications, e.g. in regenerative amplifiers. LAYERTEC produces thin film polarizers on plane substrates (dimensions according tocustomer specifications) for wavelengths between 260 nm and 2500 nm. All TFPs are optimized for high laser-induced damage thresholds.
Although there are no certified measurements available, LAYERTEC has learned from several customers that the LIDT of a TFP is approximately one third of the LIDT of a highly reflecting mirror for the same wavelength coated using the same technology.

80Selected Special Components
Thin Film Polarizers

Standard Thin Film Polarizers
Rs
100
90
80
70
60
50
40
30
20
10
0

Rs (99 – 100 %)Rp

AOI = 55°

b

R [%]

R [%]

a

1000

1020

1040

1060

1080

1100

Rp (53°)
100
90
80
70
60
50
40
30
20
10
0
1000

1020

wavelength [nm]1040

Rp (55°)1060

Rp (57°)

1080

1100

wavelength [nm]Figure 2: Reflectance spectraa) of a standard TFP for 1030 nm at AOI = 55° (Brewster’s angle) for s- and p-polarized lightb) of the same TFP design for AOI = 53°, 55° and 57° for p-polarized light (angle adjustment decreases Rp at 1030 nm from 0.25 % to < 0.1 % thus
giving the option to optimize the polarization ratio)• TFPs can be produced for AOI > 40°. Please note that thin film polarizers working at the Brewster’s angle exhibit aconsiderably broader bandwidth and a higher Tp/Ts ratio than those working at AOI = 45°.
• Typical polarization ratios Tp/Ts standard: > 500 (AOI = 45° or 55°)
• An extended wavelength range with a limited polarization ratio can be obtained by choosing AOI beyond the Brewster’s angle• Special designs with a polarization ratio of Tp/Ts up to 10 000 are possible• High laser-induced damage thresholds (useful for intra cavity applications)• It is beneficial to design the laser in a way that the polarizers can be tilted by ± 2° to adjust the polarizer to its best performance• The standard design can be used for wavelengths between 260 nm and 2500 nm

Special Thin Film Polarizers
Rs
100
90
80
70
60
50
40
30
20
10
0
600

Rp

AOI = 70°

b

R [%]

R [%]

a

650

700

750

800

850

900

950

1000

wavelength [nm]

Rs
100
90
80
70
60
50
40
30
20
10
0

600

680

760

840

Rp

920

AOI = 80°1000

wavelength [nm]Figure 3: Broadband TFPs for the wavelength range of the Ti:Sapphire laser with different bandwidths and different polarization ratios,
working at AOI = 70° and AOI = 80°a) Rp and Rs vs. wavelength, TFP designed for AOI = 70°b) Rp and Rs vs. wavelength, TFP designed for AOI = 80°

R [%]

Rs
100
90
80
70
60
50
40
30
20
10
0

700

725

750

775

Rp

800

Rp (0 – 1 %)

825

850

AOI = 65°

875

900

wavelength [nm]Figure 4: Broadband TFP for the 800 nm region

This special design provides an extremely broad polarizing wavelength range (± 10 % of the center wavelength) with Tp/Ts = 300 to 1000.

81

Selected Special Components
Low Loss Optical Components (340 – 3000 nm)

Low Loss Optical Components (340 – 3000 nm)
HR Mirrors• R > 99.99 % in the VIS and NIR spectral range• R > 99.999 % was demonstrated at several wavelengths between 1000 – 1600 nm• Mirrors with defined transmittance (e.g. T = 0.002 %)• For Cavity Ring-Down time spectroscopy, it is favorable to adjust the transmittance to the value of the scattering and absorption
losses (T = S + A)
• All mirrors for CRD experiments are delivered with rear side AR coating. Wedged substrates on request• Plane and spherically curved Fused Silica substrates• Premium polish, RMS roughness: ≤ 0.15 nm (see table 2 on page 136)
• Surface imperfection tolerance: 5/ 1 × 0.010 (ISO 10110) for Ø 25 mm• Coating technique: magnetron sputtering, ion beam sputtering• Optical parameters are stable against changes in temperature and humidity• Attractive prices for small and medium numbers of substrates per coating run• Very high reflectance values for complex coating designs, e.g. GTI laser mirrors with R > 99.95 % (see page 64 f.)• Vacuum packaging or packaging under nitrogen cover gas in dust free boxes• Designed for vacuum applicationab

T [ppm]R

R [%]100.0000
99.9995
99.9990
99.9985
99.9980
99.9975
99.9970
99.9965
99.9960
99.9955
99.9950
1000

1010

1020

1030

1040

1050

1060

T
10
9
8
7
6
5
4
3
2
1
0

1000

1010

wavelength [nm]

1020

1030

1040

1050

wavelength [nm]Figure 1: Example: low loss mirror for 1030 nm
Substrate: Fused Silica plano-concave ROC = 1000 mm polished at LAYERTEC
Coating: PR (0°, 1030 nm) > 99.9985 % + T (0°, 1030 nm) ≈ 5 ppm (magnetron sputtering)
CPI-absorption measurement A (0°, 1030 nm) < 1 ppm; S (0°, 1030 nm) = 1 – T – R – A ≈ 4 ppma) Cavity-Ring-Down measurement 0°b) Transmission measurement 0°

Important note for an order
The following balance equation applies:
1 = Reflectance R + Transmittance T + Losses L with
L = Absorbance A + Scattered Light S
Please specify the transmittance required for the application. LAYERTEC has dealt with the reduction of optical losses for many years
and knows about the typical values of absorption and scattering in the NUV, VIS and NIR spectral range. Based on this experience
LAYERTEC calculates the achievable reflectance from:
R=1-T-Ve.g.
Customer: T (0°, 633 nm) = 10 ppm (± 5 ppm)
LAYERTEC: V (0°, 633 nm) < 25 ppm (typically < 20 ppm)
Specification: R (0°, 633 nm) > 99.996 %Customer: T (0°, 390 nm) = 100 ppm (± 20 ppm)
LAYERTEC: V (0°, 390 nm) < 50 ppm
Specification: R (0°, 390 nm) > 99.983 %

82

1060

Selected Special Components
Low Loss Optical Components (340 – 3000 nm)

Cavity Ring-Down time measurements and reference data
Table 1: Reflectance and transmittance values of LAYERTEC low loss mirrors; reflectance measured by Cavity Ring-Down spectroscopy, AOI = 0°

Wavelength

Rmax

T

Loss L = 1 - R - T

Measured at

248 nm

99.87 %

0.00024 %1300 ppm

LAYERTEC GmbH266 nm

99.941 %0.0031 %560 ppm

LAYERTEC GmbH355 nm

99.983 %0.0105 %65 ppmLAYERTEC GmbH

380 nm

99.988 %0.007 %

50 ppmLAYERTEC GmbH

550 nm

99.9977 %0.00039 %19 ppmLAYERTEC GmbH633 nm

99.992 %0.006 %

20 ppmWestsächsische Hochschule Zwickau, Germany

660 nm

99.992 %0.006 %

20 ppmHeidelberg University, Germany

689 nm

99.9982 %0.0005 %13 ppmLAYERTEC GmbH798 nm

99.995 %0.003 %

10 ppmLAYERTEC GmbH

840 nm

99.9988 %0.0002 %10 ppmLAYERTEC GmbH1030 nm99.9980 %0.0012 %8 ppm

LAYERTEC GmbH

1150 nm99.9994 %0.00035 %2.5 ppm

LAYERTEC GmbH1392 nm99.9985 %0.0007 %8 ppm

TIGER OPTICS, USA (R measurement)
LAYERTEC GmbH (T measurement)

1550 nm99.999 %0.0002 %8 ppm

IPHT Jena, Germany

2350 nm99.995 %0.002 %

30 ppmUniversity of Grenoble, France

3250 nm99.928 %0.012 %

600 ppm

University of Grenoble, France

4000 nm99.9 %——

Bielefeld University, Germanya

AOI = 0°
800
700
500
400
300
200
100
0

100.00
99.99
99.98
99.97
99.96
99.95
99.94
99.93
99.92
99.91
99.90

AOI = 0°R [%]T [ppm]

600

b

650

850

1050

1250

1450

1650

650

wavelength [nm]

850

1050

1250

1450

1650

wavelength [nm]Figure 2: Example of a low loss mirror for three wavelength ranges:
PR (0°, 630 – 710 nm + 1030 – 1110 nm) = 99.98 (± 0.015) % + PR (0°, 1550 – 1565 nm) = 99.965 (± 0.025) %;T (0°, 630 – 710 + 1030 – 1110 + 1550 – 1565 nm) ≈ 100 … 400 ppm;
measured losses: (0°, 660 nm) ≈ 140 ppm; L (0°, 1070 nm) ≈ 10 ppm; L (0°, 1555 nm) ≈ 10 ppm

Notes• Losses = absorption + scattered light; with absorption << scattered light• Losses = f (polished surface, wavelength, coating technology, design and defects)• E.g. scattered light of a plane or curved surface < scattered light of a concave surface combined with a plane chamfer for bonding
The development of low loss optics is highly dynamic. The tabular values are therefore guidelines for specific customer requests.

83

Selected Special Components
Coatings on Crystal Optics (340 – 3000 nm)

Coatings on Crystal Optics (340 – 3000 nm)
Laser applications using crystal optics have reached a high standard in industry and research. Optical coatings on crystals are an essential
part of modern laser designs. They cover a wide range from single wavelength AR coatings on laser and nonlinear optical crystals up tocomplex multilayer coatings providing several high reflectance and high transmittance wavelength ranges and thus, replacing external laser
mirrors. LAYERTEC has a lot of experience in coating laser crystals. LAYERTEC coatings are used in industrial high power Q-switched andcw lasers of several laser manufacturers. The quality of coatings on crystals depends on the coating technique as well as on the surface
quality of the crystal. All coatings are produced using sputtering techniques which guarantee very low scattering losses and high environmental stability of the optical parameters.
The rapid progress in crystal growth techniques resulted in a wide variety of new crystals for laser applications, e.g. laser crystals liketungstanates and vanadates or nonlinear optical crystals like RTP. Each crystal type requires optimized polishing procedures and coating
techniques. The coating design is determined by the optical properties of the crystal. However, the thermal expansion coefficients and thesurface quality after storage and transport influence the coating quality as well. Especially, hygroscopic crystals like LBO or BBO require
special pretreatments to achieve high damage thresholds and long lifetime for the coatings. Thus, coatings on new crystals always require
experimental investigations to find the best coating procedures. Different dimensions and uncommon sizes and shapes are possible using
the special LAYERTEC coating technology. The following table gives an overview about the crystals which have already been coated at
LAYERTEC and the types of layer systems which have been applied successfully.
Table 1: Examples of available coatings on crystals

Crystal Type

AR/BBAR

Single HR optional with HT

Double HR/BBHR optional with HT

α-SiO2 (Quartz)

x

x

x

BBO

x

—

—

BiBO

x

x

CaCO3

x

CdMnTex

CTAx

Nd:GdVO4xx

Nd:GGGx

x

Nd:Cr:GSGG

x

x

KTA

x

x

KTP

x

x

x

Yb:KGW, Yb:KYW

x

x

x

LBO

x

—

—

LiNbO3x

LMA

x

Nd:LSB

x

x

x

RTP

x

Ruby

x

x

x

Ti:Sapphire

x

x

x

Spinellxx

x

Cr:YAGx

x

x

Er:YAGxx

x

Ho:YAGx

x

x

Nd:YAG, Yb:YAG

x

x

x

Nd:YALO (YAP)

x

YLF

x

Nd:YVO4

x

x

x

ZGP

x

ZnSe

x

x

x

x:
established coating process—:
not possible due to technical reasons
empty box: not requested yet

Detailed measurement reports are available for each batch. Do not hesitate to contact LAYERTEC for a discussion or a quotation regarding
your special coating project.

84Selected Special Components
Coatings on Crystal Optics (340 – 3000 nm)

Coatings on Doped Laser Crystals

1.0

80

0.8

60

0.6

R [%]

R [%]

AOI = 0°

R

100

40

0.4

20

0.2

0
450

550

650

750

850

950

1050

0

1150

900

950

1000

wavelength [nm]

1050

1100

wavelength [nm]Figure 1: Reflectance spectrum of a dual HR mirror with an HT region forpumping with a laser diode (on Nd:YAG):
HR (0°, 532 nm + 1064 nm) + HT (0°, 808 nm)

Figure 2: Reflectance spectrum of an AR coating for an Yb:KYW crystal:
AR (0°, 1030 nm) < 0.2 % + AR (0° – 30°, 980 nm) < 0.2 %.
Please note the large acceptance angle for the pump radiation

Sputtered coatings on laser rods, discs and slabs with:• High laser-induced damage thresholds for critical industrial applications of Q-switched and cw lasers• Low residual reflectance• Broadband and multiple wavelength AR coatings• Complex HR and HR/HT-coatings for compact laser designs, e.g. HR (0°, 532 nm + 1064 nm) > 99.9 % + R (0°, 808 nm) < 5 %,on Nd:YVO4 for diode-pumped and frequency-doubled “green” lasers)• Coating of crystals with variable or special sizes and shapes• Coating of the full aperture of small crystals

Coatings on Nonlinear Optical Crystals

2.0

4

1.6

3

1.2

R [%]

R [%]

AOI = 0°
5

2

0.8

1

0.4

0

900

1400

1900

2400

2900

R

0.0
650

3400

700

750

wavelength [nm]Figure 3: Reflectance spectrum of a triple wavelength AR coating on KTP:
AR (0°, 1064 nm + 1575 nm + 3400 nm) < 0.5 %900

AOI = 0°

R [%]

6
4
2
400

500

600

700

800

950

Figure 4: Reflectance spectrum of an AR-coating:
AR (0°, 750 – 850 nm) < 0.5 % on CdMnTe

8
R [%]

850

R

10

0
300

800
wavelength [nm]

900

1000

wavelength [nm]Figure 5: Reflectance spectrum of a triple wavelength AR-coating:
R (0°, 343 nm + 515 nm + 1030 nm) < 0.75 % on BBO

1100

100
90
80
70
60
50
40
30
20
10
0

450

550

650

750

850

950

1050

1150

wavelength [nm]Figure 6: Reflectance spectrum of a dichroic mirror on KTP:
R (0°, 532 nm) < 1 % + HR (0°, 1064 nm) > 99.95 %85

Metallic Coatings

Metallic Coatings

Chapter Index
Front Surface Silver Mirrors (400 – 4000 nm)....................87
Broadband Silver Mirrors for the VIS and NIR.........................87
Silver Mirrors for Use in Ultrafast Lasers..................................88
Silver Mirrors with Enhanced Reflectance...............................88
Front Surface Aluminum Mirrors (150 – 900 nm)..............90
Broadband Mirrors for the UV, VIS and NIR............................90
Aluminum Mirrors for Multiple Wavelength andUltrafast Applications.............................................................90
Protected Aluminum Mirrors for the DUV and VUV................91
Enhanced Aluminum Mirrors for 157 nm................................92
Enhanced Aluminum Mirrors for 193 nm................................92
Special Metallic Coatings (400 – 10 000 nm).....................93
Chromium Coatings for Optical Applications..........................93
Broadband Neutral Density Filters for the NIR.........................93
Solderable Coatings................................................................93
Gold Mirrors for the NIR Spectral Range.................................94
Partially Transmissive Gold Layers for Optical andNon-optical Applications........................................................94

86

Metallic Coatings
Front Surface Silver Mirrors (400 – 4000 nm)

Front Surface Silver Mirrors (400 – 4000 nm)
Broadband Silver Mirrors for the VIS and NIR
AOI = 0°
100
98
96
94
92
90
88
86
84
82
80

b

R [%]

R [%]

a

600

700

800

900

1000

AOI = 0°
100
98
96
94
92
90
88
86
84
82
80

600

800

1000

wavelength [nm]

c

R [%]

1200

1400

1600

1800

2000

wavelength [nm]AOI = 0°
100
98
96
94
92
90
88
86
84
82
80

1000

2800

4600

6400

8200

10000

wavelength [nm]Figure 1: Reflectance spectra of three standard types of protected silver
mirrors:a) Optimized for 600 – 1000 nm with R > 98 %b) Optimized for 600 – 2000 nm, 600 – 750 nm with R > 96 %,750 – 2000 nm with R > 98 %c) Optimized for 1000 – 10 000 nm with R > 98 %Optical Properties• R > 98 % throughout the specified wavelength range (except figure 1b)• R = 94 … 97 % in the VIS outside the specified wavelength range• R > 97 % in the NIR outside the specified wavelength range

Special Features• Silver has the highest reflectance of all metals in the VIS and NIR• Sputtered protective layers yield very stable optical parameters• Lifetime of more than 10 years in normal atmosphere has been demonstrated although unprotected silver is chemically unstable• The high atomic density of sputtered coatings guarantees that even very thin protective layers (≈ 20 nm) provide a good protection
against the atmosphere• The thickness of the protective layer can be used to optimize the reflectance of the mirrors for different wavelength ranges(see figure 1)• Sputtered silver mirrors show extremely low scattering losses. (total scattering TS ≈ 30 ppm in the VIS and NIR)
• Silver mirrors with defined transmittance (e.g. T = 0.01 %) on request (see 52 f.)• Mechanical stability of protected silver mirrors is tested according to MIL-M-13508C § 4.4.5• Maximum diameter: 600 mm, especially for astronomical applications

87

Metallic Coatings
Front Surface Silver Mirrors (400 – 4000 nm)

Silver Mirrors for Use in Ultrafast Lasers
Rs
100
99
98
97
96
95
94
93
92
91
90

Rp

Ru

AOI = 45°b

GDD [fs2]

R [%]

a

600

700

800

900

1000

10
8
6
4
2
0
-2
-4
-6
-8
-10

600

650

700

wavelength [nm]

750

800

s-pol

p-pol

AOI = 45°

850

900

950

1000

wavelength [nm]Figure 2: Reflectance and GDD spectra of a silver mirror optimized for use with ultrafast lasers in the wavelength range 600 – 1000 nm (AOI = 45°)a) Reflectance vs. wavelengthb) GDD vs. wavelength

Silver mirrors are ideal in ultrafast laser systems because of their extremely broad low-GDD reflectance band. For more examples see page
52 f.

Silver Mirrors with Enhanced Reflectance
The reflectance of silver mirrors can be enhanced for selected wavelengths or wavelength regions by a dielectric protective coating. Figure
3 to figure 5 show examples for silver mirrors with enhanced reflectance. Such mirrors combine very high reflectance at the wavelengths
of interest with a relatively high reflectance throughout the VIS which makes them ideal for use in conjunction with alignment lasers.

Mirrors for Astronomical Applications
AOI = 0°
100
99
98
97
96
95
94
93
92
91
90

b

R [%]

R [%]

a

350

450

550

650

750

850

wavelength [nm]AOI = 45°
100
99
98
97
96
95
94
93
92
91
90

350

450

550

Figure 3: Reflectance spectra of an enhanced silver mirror which shows R ≥ 98 % throughout the visible spectral range:a) AOI = 0°b) AOI = 45°, unpolarized lightR [%]AOI = 0°
100
96
92
88
84
80
76
72
68
64
60

400 450

500

550

600

650

700

750

800

850

900 950

wavelength [nm]Figure 4: Silver mirror with enhanced reflectance at 425 and 850 nm(R > 99.5 %)

88

650

wavelength [nm]

750

850

Metallic Coatings
Front Surface Silver Mirrors (400 – 4000 nm)

Turning Mirrors for 1030 nm
AOI = 45°
100

R [%]

90

80

70

400

600

800

1000

1200

wavelength [nm]Figure 5: Silver based turning mirror with enhanced reflectance for 45°,1030 nm and R > 80 % for any alignment laser in the red spectral range

The mirror in figure 5 is a cost-effective alternative for all dielectric mirrors for high power Yb:YAG or Nd:YAG lasers.
LIDT Info
50 kW/cm², wavelength: 1030 nm, cw
tested without destruction

Scanning Mirrors
AOI = 22°
100
95
90
85
80
75
70
65
60
55
50
630

AOI = 45°

AOI = 58°

b

R [%]

R [%]

a

640

650

660

670

AOI = 22°
100
99
98
97
96
95
94
93
92
91
90

wavelength [nm]

700

760

820

AOI = 58°

AOI = 45°

880

940

1000

wavelength [nm]Figure 6: Reflectance spectra of a dielectrically enhanced silver mirror which can be used as scanning mirror for laser diodes in the NIR:
HRu (22° – 58°, 805 – 940 nm) > 99.3 %+ Ru (22° – 58°, 630 – 670 nm) > 50 %For more information on enhanced silver mirrors see page 18, 52 f. and 76 f.

89

Metallic Coatings
Front Surface Aluminum Mirrors (150 – 900 nm)

Front Surface Aluminum Mirrors (150 – 900 nm)

R [%]Broadband Mirrors for the UV, VIS and NIR

100
95
90
85
80
75
70
65
60
55
50

190

protected Al (standard)

unprotected Al

390

790

590

AOI = 0°

990

1190

wavelength [nm]Figure 1: Reflectance spectra of unprotected aluminum and of a standard
protected aluminum mirror

Optical Properties
Unprotected aluminum:• R > 80 % at 193 nm• R = 92 % at 248 nm• R > 85 % from 200 nm to 950 nm• R > 90 % from 230 nm to 600 nm• R > 90 % for λ > 1 µm

Standard mirror:• R = 82 … 92 % from 240 nm to 550 nm• R = 85 … 92 % from 550 nm to 950 nm• R > 92 % for λ > 1 µm

Aluminum is the metal with the highest reflectance in the UV spectral range. Besides this, aluminum has a high and relatively constantreflectance in the VIS and NIR. The minimum in the reflectance curve around 800 nm is due to a phonon resonance and can only be overcome by a dielectric protective coating. The reflectance in the VIS and UV spectral range can be influenced by the coating technologies.
In case of protected aluminum mirrors, the positions of the minima and maxima of the reflectance depend on the design of the protective
layer system and on the angle of incidence (AOI). Please specify AOI and the wavelengths of interest so that reflectance may be optimized
as much as possible.
Maximum diameter: 600 mm, especially for astronomical applications.

Aluminum Mirrors for Multiple Wavelength and Ultrafast Applications
Rs
100
97
94
91
88
85
82
79
76
73
70

Rp

Ru

AOI = 45°

b

s-pol
15
10
5
0
-5
-10
-15

250

350

450

550
wavelength [nm]

650

750

850

-20

250

350

450

550

650

750

850

wavelength [nm]Figure 2: Reflectance and GDD spectra of an aluminum mirror optimized for R > 85 % at 266 nm, 400 nm and 800 nm (AOI = 45°)a) Reflectance vs. wavelengthb) GDD vs. wavelength

Figure 2 shows the reflectance spectra of a mirror optimized for high reflectance at 266 nm, 400 nm and 800 nm at AOI = 45°.

90

p-pol

20

GDD [fs2]

R [%]

a

950

Metallic Coatings
Front Surface Aluminum Mirrors (150 – 900 nm)

aenhanced 1

enhanced 2

AOI = 0°

b

100

R [%]

GDD [fs2]

90

80

70
200

250

300

350

400

450

500

enhanced 1
20
16
12
8
4
0
-4
-8
-12
-16
-20

200

250

wavelength [nm]

300

350

400

enhanced 2

450

500

wavelength [nm]Figure 3: Reflectance and GDD spectra of aluminum mirrors with different designs for enhanced reflectancefor the third harmonic of the Ti:Sapphire laser (AOI = 0°)a) Reflectance vs. wavelengthb) GDD vs. wavelength

Special Features• High reflectance in the wavelength range specified• Extremely low scattering losses of protected aluminum mirrors(total scattering TS < 100 ppm at 633 nm, TS < 1000 ppm at 248 nm, TS < 5000 ppm at 193 nm)• Standard mirrors can be cleaned using ethanol or acetone and are resistant to moderate abrasion(tested according to MIL-M-48497A § 4.5.4.2 and § 4.5.3.3)• All mirrors are resistant to humidity (tested according to MIL-M-13508C §4.4.7)• Highly stable optical parameters because of sputtered SiO2 protective layer

Protected Aluminum Mirrors for the DUV and VUV

R [%]optimized 157 nm
100
90
80
70
60
50
40
30
20
10
0

120

140

160

optimized 193 nm

180

200

AOI = 0°220

wavelength [nm]Figure 4: UV optimized aluminum: reflectance spectra of aluminum mirrors optimized for 157 nm and 193 nm (AOI = 0°)

Optical Properties
Special coating design depending on the wavelengths of interest:• Optimized for 157 nm: R = 74 … 78 % for 157 nm (R > 70 % from 150 to 200 nm)• Optimized for 193 nm: R = 75 … 80 % for 193 nm• Optimized for 248 nm: R > 90 % for 248 nm

91

Metallic Coatings
Front Surface Aluminum Mirrors (150 – 900 nm)

Enhanced Aluminum Mirrors for 157 nm
100
90
80
70
60
50
40
30
20
10
0
120

R (0°)Ru (45°)

b

R [%]

R [%]

a

140

160

180

200

220

AOI = 0°
100
90
80
70
60
50
40
30
20
10
0
120

140

160

wavelength [nm]

180

200

220

wavelength [nm]Figure 5: Reflectance spectra of two types of enhanced aluminum mirrors for 157 nm:a) R > 80 % for AOI = 0° … 45°b) R > 94 % at AOI = 0°

• Reflectance at 157 nm can be further improved by dielectric protective coatings (up to R > 94 %)• Reflectance in the VIS: R = 60 … 80 %. This can be used for an alignment laser• Especially mirrors with R = 85 … 90 % can be used at a wider range of AOI than all dielectric mirrors of this reflectance

Enhanced Aluminum Mirrors for 193 nm

R [%]Measurement

Rs

Rp

AOI = 45°100

• This kind of mirrors can also be used as scanning mirror for
AOI = 45° – 50° with Ru > 93 %80

• Reflectance in the VIS: R = 60 … 80 %. This can be used foran alignment laser

60• VUV optimized mirrors should be treated with extreme care

40
20
0

130

150

170

190

210

230

wavelength [nm]Figure 6: Reflectance spectra of an aluminum mirror with enhanced reflectance for 193 nm (AOI = 45°, Ru > 95 %)92• Reflectance at 193 nm can be improved up to Ru > 95 %Metallic CoatingsSpecial Metallic Coatings (400 – 10 000 nm)

Special Metallic Coatings (400 – 10 000 nm)
Chromium Coatings for Optical Applications
Chromium coatings are used for lithographic processes and other special optical applications. LAYERTEC offers chromium coatings withextremely low pinhole density on mask blanks and silicon wafers. Typical substrates sizes are 6 inch × 6 inch, but uncommon sizes up to
diameter 600 mm are also possible. LAYERTEC uses specialized sputtering processes for very efficient industrial production. These processes are optimized for:• Low pinhole density• High optical density• Low mechanical stress• High electrical conductivity
Besides high volume coating manufacturing, LAYERTEC still maintains its capabilities for flexible production of small volumes such as OEM
components or components for research and development. Do not hesitate to contact LAYERTEC regarding your special request.

T [%]Broadband Neutral Density Filters for the NIR

100
90
80
70
60
50
40
30
20
10
0

T = 60 %T = 36 %T = 12 %AOI = 0°• Nearly constant transmittance for broad wavelength range
from 1 µm to 10 µm• Substrate: BaF2
• Other transmittance values on request

1000

5000

9000

13000

17000

wavelength [nm]Figure 1: Transmittance spectra of broadband neutral density filters withdifferent transmittance values

Solderable Coatings
Soldering is one of the most important mounting techniques for optics which require excellent thermal contact to a heat sink. LAYERTEC hasdeveloped several coating designs containing gold and other metals which can be used for soldering of the optics. A very special problem
is to solder coatings on components for high power applications. As an example figure 2 show a pump mirror which is coated with a solder layer system on the top side and with dielectric coatings on the front and rear surfaces. Extreme care must be taken to avoid metallic
contaminations on the optical surfaces. Nevertheless, the solder coating has to cover the whole top surface of the substrate.
ab

Figure 2: Pump mirror which is coated with a solderable layer on the top side93

Metallic CoatingsSpecial Metallic Coatings (400 – 10 000 nm)

R [%]Gold Mirrors for the NIR Spectral Range

100
98
96
94
92
90
88
86
84
82
80

unprotected

600

800

1000

1200

1400

1600

AOI = 0°

1800

2000

wavelength [nm]Figure 3: Reflectance spectrum of an unprotected gold mirror

Figure 4: Gold mirror on plano-concave substrate

Optical Properties
Unprotected gold:• R > 97 % from 700 nm to 1 µm
• R > 98 % for λ > 1 µm to 20 µm

Special Features• Extremely low scattering losses (total scattering TS < 100 ppm at 633 nm)• Gold mirrors are chemically stable and can be used without protective layer• Unprotected gold is soft and scratches easily• Protected mirrors can be cleaned (tested according to MIL-M-13508C § 4.4.5)

T [%]Partially Transmissive Gold Layers for Optical and Non-optical Applications

100
90
80
70
60
50
40
30
20
10
0

10 nm

500

700

900

20 nm

1100

40 nm

1300

wavelength [nm]Figure 5: Transmittance of partially transparent gold coatings on sapphire

Gold coatings with a thickness of 10 nm to 50 nm can be used as partial reflectors or attenuators in the NIR spectral range. Figure 5 showstransmittance spectra of gold layers with different thickness. Moreover, thin gold layers are also useful for non-optical applications. An
example of such an application is the generation of single electron pulses. Thin metallic layers are irradiated with femto-second laser pulses.
This results in the release of electrons. These electron pulses are generated with the repetition rate of the ultrafast laser. The pulse lengthof these electron pulses can be compressed to the attosecond range using a microwave cavity [1, 2]. Magnetron sputtering allows the
manufacture of partially transmissive gold layers in the mentioned thickness range. The optical parameters of these coatings are very stablebecause gold is chemically inert. Please note that gold layers are soft and can be easily damaged mechanically.

Literature[1] A. Gliserin, A. Apolonski, F. Krausz, P. Baum: “Compression of single electron pulses with a microwave cavity”; New Journal of Physics 14(2012)073055 (18 pp)[2] M. Aidelsburger, F. O. Kirchner, F. Krausz and P. Baum: “Single-electron pulses for ultrafast diffraction”; PNAS Vol.107, No.46, pages 19714-19719

94

Standard Items from StockStandard Items from Stock
Chapter Index
The LAYERTEC Standard Items.........................................97
Specifications of Plane Substrates.....................................98
Specifications of Curved Substrates................................100
Excimer Lasers [193 nm, 248 nm, 308 nm].......................102
Turning Mirror 45°, 193 nm..................................................102
Turning Mirror 45°, 248 nm..................................................102
Turning Mirror 45°, 308 nm..................................................102
Window 0°, 193 nm.............................................................102
Window 0°, 248 nm.............................................................103
Window 0°, 308 nm.............................................................103
fs-Laser [TiSa, up to 150 nm bandwidth]..........................104
Laser Mirror 0° ....................................................................104
Laser Mirror 0°, high power.................................................104
Pump Mirror 5°....................................................................105
Turning Mirror 22.5°............................................................105
Turning Mirror 45° ..............................................................105
Turning Mirror 45°, p-pol.....................................................105
Turning Mirror 45°, high power ...........................................106
Separator 0°, 750 – 850 / 360 – 450 nm..................................106
Separator 45°, 760 – 850 / 350 –450 nm................................106
Laser Mirror 0 – 45° .............................................................106
Chirped Mirror 5° ................................................................107
Chirped Mirror Pair 5°, -40 fs2 ..............................................107
Chirped Mirror Pair 5°, -80 fs2 ..............................................107
Chirped Mirror Pair 5°, -110 fs2 ............................................107
Beamsplitter 45°, s-pol.........................................................108
Beamsplitter 45°, p-pol........................................................108
Window 0°..........................................................................108
fs-Laser [TiSa, 300 nm bandwidth]...................................109
Laser Mirror 0°.....................................................................109
Pump Mirror Pair 0°.............................................................109
Turning Mirror 22.5°............................................................110
Turning Mirror 45°, p-pol.....................................................110
Turning Mirror 45°, s-pol......................................................110
Turning Mirror 45°...............................................................110
Laser Mirror 0 –45°...............................................................111
Chirped Mirror Pair 5°..........................................................111
Beamsplitter 45°, p-pol........................................................111
Beamsplitter 45°, s-pol.........................................................112
Polarizer 75°........................................................................112
Window 0°..........................................................................112
ps/fs-Laser [1030–1040 nm].............................................113
Laser Mirror 0°.....................................................................113
Pump Mirror 0°, 800 – 982 nm .............................................113
Pump Mirror 0°, 960 – 982 nm .............................................114
Turning Mirror 45°...............................................................114
GTI-Mirror 5°, 1 030 nm, -250 fs2 ..........................................114
GTI-Mirror 5°, 1 030 nm, -550 fs2 ..........................................114
GTI-Mirror 5°, 1 030 nm, -1 000 fs2 .......................................115
GTI-Mirror 5°, 1 040 nm, -250 fs2 ..........................................115
GTI-Mirror 5°, 1 040 nm, -550 fs2 ..........................................115
GTI-Mirror 5°, 1 040 nm, -1 000 fs2 .......................................115
Separator 22.5°....................................................................116
Thin Film Polarizer 45°, 1 030 nm .........................................116
Thin Film Polarizer 45°, 1 042 nm .........................................116
Thin Film Polarizer 56°, 1 030 nm .........................................116
Thin Film Polarizer 56°, 1 042 nm .........................................116
Window 0°..........................................................................116

cw/ns-Laser [1030–1064 nm]...........................................117
Laser Mirror 0°.....................................................................117
Pump Mirror 0°....................................................................117
Turning Mirror 22.5 – 45°, 1 030 – 1 064 nm ..........................118
Turning Mirror 22.5 – 45°, 515 – 532 nm ..............................118
Turning Mirror 45°, 1 030 – 1 064 nm ...................................118
Turning Mirror 45°, 515 – 532 nm ........................................118
Turning Mirror 45°, 343+515+1 030 nm ...............................118
Turning Mirror 45°, 355+532+1 064 nm ...............................119
Non-Polarizing Beamsplitter 45°, 1 030 nm ...........................119
Non-Polarizing Beamsplitter 45°, 1 064 nm ...........................119
Non-Polarizing Beamsplitter 45°, 515 nm .............................119
Non-Polarizing Beamsplitter 45°, 532 nm .............................120
Separator 45°, 515 – 532 / 1 030 – 1 064 nm...........................120
Separator 45°, 1 030 / 515 nm ..............................................120
Separator 45°, 1 064 / 532 nm ..............................................120
Separator 45°, p-pol. 343 / 515 / 1 030 nm.............................121
Separator 45°, p-pol. 355 / 532 / 1 064 nm.............................121
Separator 45°, s-pol. 343 – 355 / 515 – 532 / 1 030 – 1 064 nm .........121
Thin Film Polarizer 56°, 1 030 nm .........................................122
Thin Film Polarizer 56°, 1 064 nm .........................................122
Thin Film Polarizer 56°, 515 nm ............................................122
Thin Film Polarizer 56°, 532 nm ............................................122
Window 0°..........................................................................122
2 μm [Ho:YAG | Tm:YAG]...................................................123
Turning Mirror 45° ..............................................................123
Output Coupler 70 % ..........................................................123
Output Coupler 80 % ..........................................................123
Output Coupler 95 % ..........................................................124
GTI-Mirror 5°, -500 fs2 .........................................................124
Short Wave Pass Filter 45° ...................................................124
Thin Film Polarizer 55° .........................................................124
3 μm [Er:YAG]..................................................................125
Laser Mirror 0°, high power ................................................125
Output Coupler 80 % ..........................................................125
Output Coupler 85 % ..........................................................125
Output Coupler 90 % ..........................................................126
Turning Mirror 45°, Red R > 95% ........................................126
Turning Mirror 45°, Red R < 20% ........................................126
Metallic Mirrors...............................................................127
Unprotected Gold Mirror .....................................................127
Protected Gold Mirror .........................................................127
Protected Silver Mirror, 600 – 1 000 nm .................................127
Protected Silver Mirror, 800 – 2 000 nm ................................128
Protected Aluminum Mirror, UV-range .................................128
Protected Aluminum Mirror, UV-VIS-range ...........................128
Low Loss Mirrors for CRD-Measurements ......................129
Principal Curves of Reflectance and Transmittance................129
Low Loss Mirror Set for High Finesse Cavities ................130
Plane / Plane Substrate.........................................................130
CC 1 000 / Plane Substrate....................................................130
Beam Expanders.............................................................132
Lenses 0°, 800 nm ...............................................................132
Lenses 0°, 1 000 nm .............................................................132

95

Standard Items from Stock96

Standard Items from StockStandard Items from StockStandard Items from Stock2

Choose type of laser

Please do not hesitate to contact us for a quotation or a discussion regarding your special requirements, especially if they are not mentioned in this catalog. We are looking forward to complex tasks. Simply contact us at info@layertec.de.
Choose type of laser

How to Order

LAYERTEC Item Numbers

Choosetype
opticalelement / coating
1. Chooseof laserTo order an optical component, you need the item number. Please
note, that the item number is not identical with the coating number.

2. Choose
optical element/ coatingChooseoptical element/ coating

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
450

3

Example: 1 coating number 141321 applied on 3 different
substrates

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
450

p

R [%]

1

The LAYERTEC Standard Items are kept in stock for you and will be shipped by return. You can order the components through our webshop
at www.layertec.de or by e-mail.

ps

Coating
numbers
wavelength [nm]

470

490

510

530

550

570

590

610

630

650

wavelength [nm]
470

490

510

530

550

570

590

610

630

650

Choose size of substrate

3. Choose size and shape of substrate on page 98 ff
Choose size of substrate

Itemnumber

How LAYERTEC item numbers are generated

Order online at www.layertec.de

Orderatonlineat www.layertec.de
4 Order4.online
www.layertec.de

Coating# S2(^) ABCDEF+
Substrate# A1...T1+
Coating# S1 GHIJKL=
Item# MNOPQR

Main Function Side: S2(^)
LAYERTEC marks the main function side eiter with an arrow ora dot (items thinner than 1 mm). On items with edge thickness
above 1 mm, also the coating batch is included. For all fused silica
substrates, laser engraving is used.

^

S2(^)
(main function side)97

Standard Items from StockSpecifications of Plane Substrates

No.

A1
A2
A3
A4
A5

B1
B2
B3
B4
B5

C1
C2
C3

D1

K1

Material

Length /DiameterThickness

A1

Fused Silica

Ø 12.7 mm (-0.1 mm)

0.5 mm (±0.1 mm)

A2

Fused Silica

Ø 12.7 mm (-0.1 mm)

1.0 mm (±0.1 mm)

A3

Fused Silica

Ø 12.7 mm (-0.1 mm)

3.05 mm (±0.1 mm)

A3 e

SapphireØ 12.7 mm (-0.1 mm)

3.0 mm (±0.1 mm)

A4

Fused Silica

Ø 12.7 mm (-0.1 mm)

6.35 mm (±0.1 mm)A4 b

Fused Silica (IR grade)Ø 12.7 mm (-0.1 mm)

6.35 mm (±0.1 mm)

A5

Fused Silica

Ø 12.7 mm (-0.1 mm)

9.5 mm (±0.2 mm)

B1

Fused Silica

Ø 25.0 mm (-0.1 mm)

0.5 mm (±0.1 mm)

B2

Fused Silica

Ø 25.0 mm (-0.1 mm)

1.0 mm (±0.1 mm)

B3

Fused Silica

Ø 25.0 mm (-0.1 mm)

3.05 mm (±0.1 mm)

B3 b

Fused Silica (IR grade)Ø 25.0 mm (-0.1 mm)

3.0 mm (±0.1 mm)

B3 c

Fused Silica (248 nm grade)Ø 25.0 mm (-0.1 mm)

3.05 mm (±0.1 mm)

B3 d

Fused Silica (193 nm grade)Ø 25.0 mm (-0.1 mm)

3.0 mm (±0.1 mm)

B3 e

SapphireØ 25.4 mm (-0.1 mm)

3.0 mm (±0.1 mm)

B3 f

CaF₂ (193 nm grade)Ø 25.0 mm (-0.1 mm)

3.0 mm (±0.1 mm)

B4

Fused Silica

Ø 25.0 mm (-0.1 mm)

6.35 mm (±0.1 mm)

B4 b

Fused Silica (IR grade)Ø 25.0 mm (-0.1 mm)

6.35 mm (±0.1 mm)

B4 f

CaF₂ (UV grade)Ø 25.0 mm (-0.1 mm)

6.35 mm (±0.1 mm)

B4 g

Fused Silica

Ø 25.0 mm (-0.1 mm)

6.35 mm (±0.1 mm)

B4 h

ULE

Ø 25.0 mm (-0.1 mm)

6.35 mm (±0.1 mm)

B5

Fused Silica

Ø 25.0 mm (-0.1 mm)

9.5 mm (±0.2 mm)

C1

Fused Silica

Ø 50.0 mm (-0.1 mm)

3.05 mm (±0.1 mm)

C1 f

CaF₂ (UV grade)Ø 50.0 mm (-0.1 mm)

5.0 mm (±0.1 mm)

C2

Fused Silica

Ø 50.0 mm (-0.1 mm)

6.35 mm (±0.1 mm)

C3

Fused Silica

Ø 50.0 mm (-0.1 mm)

9.5 mm (±0.2 mm)

D1

Fused Silica

Ø 76.2 mm (-0.1 mm)

12.5 mm (±0.2 mm)

K1

Fused Silica

25 × 25 mm2 (-0.1 mm)

3.05 mm (±0.1 mm)

K2

Fused Silica

25 × 25 mm2 (-0.1 mm)

6.35 mm (±0.1 mm)

K3

Fused Silica

25 × 25 mm2 (-0.1 mm)

9.5 mm (±0.2 mm)

N1

Fused Silica

40 × 10 mm2 (-0.1 mm)

12.5 mm (±0.2 mm)

O1 f

CaF₂ (UV grade)

50 × 27 mm2 (-0.1 mm)

3.0 mm (±0.1 mm)

O2

Fused Silica

50 × 27 mm2 (-0.1 mm)

6.35 mm (±0.1 mm)

K2
K3

N1

O1
O2
98

Standard Items from StockSpecifications of Plane Substrates

S1

plane

S1

plane

S2

plane

//

< 5'

Clear Aperture Øe

plane

plane

plane

plane

plane

plane

plane

plane

plane

3 / 0.5 (0.2)λ/10 reg.

A1

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

A2

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

A3

3 / 247 nm (247 nm)

3 / 1 (1)

λ/2

A3 e

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

A4

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

A4 b

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

A5

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

B1

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

B2

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

B3

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

B3 b

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

B3 c

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

B3 d

3 / 247 nm (247 nm)

3 / 1 (1)

λ/2

B3 e

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

B3 f

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

B4

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

B4 b

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

B4 f

see page 130

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

B4 g

see page 130

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

B4 h

20 mm

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

B5

25 mm

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

C1

40 mm

3 / 137 nm (137 nm)

3 / 0.5 (0.2)

λ/4

C1 f

30 mm

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

C2

40 mm

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

C3

60 mm

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

D1

3 / 137 nm (55 nm)

3 / 0.5 (0.2)λ/10 reg.

K1

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

K2

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

K3

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

N1

3 / 1100 nm (1100 nm)

3 / 4 (4)

2λ

O1 f

3 / 55 nm (55 nm)

3 / 0.2 (0.2)

λ/10

O2

10 mm

plane

plane

< 5'

< 5'

< 5'

< 5'

No.

3 / 137 nm (55 nm)

20 mm
plane

Uncoated Surface Form Tolerance with λ = 546 nm

20 mm

plane

plane

plane

< 5'

32 × 8 mm2

plane

plane

plane

< 5'

42 × 23 mm299

Standard Items from StockSpecifications of Curved Substrates

No.

Uncoated Surface Form Tolerance with λ = 546 nm

Clear
Aperture Øe

//

S2

S1

R1
R2
R3
R4
R5
R6
R7
R8

3 / – (55 nm)

3 / – (0.2)λ/10 reg.

10 mm

< 5'

CC (concave)plane

3 / – (55 nm)

3 / - (0.2)λ/10 reg.

20 mm

< 5'

CC (concave)plane

3 / – (55 nm)

3 / - (0.2)λ/10 reg.

see page 130< 5'

CC (concave)

plane

centr. < 4'

CC (concave)

plane

centr. < 4'

CX (convex)

plane

R9
R10
R11
R12
R13
R14

S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
S11
S12
S13
S14

T1 a
T1 b
L1 a
L1 b
L1 c

15 mm
3 / – (55 nm)

3 / - (0.2)λ/10 reg.

L1 d

15 mm
20 mm
20 mm

L2 a
L2 b
L2 c
L2 d

100

3 / – (55 nm)

3 / - (0.2)λ/10 reg.

30 mm

Standard Items from StockSpecifications of Curved Substrates

ROC

Length /DiameterThickness

MaterialNo.

25 mm (± 0.5 %)R1

38 mm (± 0.5 %)R2

50 mm (± 0.5 %)R375 mm (± 0.5 %)R4

100 mm (± 0.5 %)

R5

R2
…
R12

125 mm (± 0.5 %)

R6

R13

150 mm (± 0.5 %)200 mm (± 0.5 %)Ø 12.7 mm(- 0.1 mm)

6.35 mm(± 0.1 mm)

Fused Silica

R7
R8

250 mm (± 0.5 %)R9300 mm (± 0.5 %)R10

500 mm (± 0.5 %)R11750 mm (±1.0 %)R121000 mm (±1.0 %)R13
3.0 mm(± 0.1 mm)

1000 mm (±1.0 %)

YAG

R1

R14

R14

S1
S2
…
S12
S13

25 mm (±0.5 %)S1

38 mm (±0.5 %)S250 mm (±0.5 %)S375 mm (±0.5 %)S4

100 mm (±0.5 %)S5125 mm (±0.5 %)S6150 mm (±0.5 %)200 mm (±0.5 %)Ø 25.0 mm(- 0.1 mm)

6.35 mm(±0.1 mm)Fused Silica

S7

S9

300 mm (±0.5 %)S10500 mm (±0.5 %)S11750 mm (±1.0 %)S121000 mm (±1.0 %)S13
3.0 mm(± 0.1 mm)

1000 mm (±1.0 %)Ø 25.0 mm(- 0.1 mm)

6.35 mm(±0.1 mm)

YAG

S14

Fused Silica

T1 a

ULE

T1 b

75 mm (±0.5 %)

L1 a
L1 b
…
L1 c
L1 d

L1 a

25 mm (±0.5 %)50 mm (±0.5 %)T1

S8

250 mm (±0.5 %)1000 mm (±1.0 %)S14

Ø 25.0 mm(- 0.1 mm)

6.35 mm(±0.1 mm)Fused Silica

L1 b
L1 c

100 mm (±0.5 %)L1 d

125 mm (±0.5 %)

L2 a

L2 a
150 mm (±0.5 %)175 mm (±0.5 %)200 mm (±0.5 %)Ø 50.0 mm(- 0.1 mm)

6.35 mm(±0.1 mm)Fused Silica

L2 b
L2 c

L2 b
…
L2 c

L2 d

L2 d
101

Standard Items from Stock
Excimer Lasers [193 nm, 248 nm, 308 nm]

Excimer Lasers [193 nm, 248 nm, 308 nm]
Turning Mirror 45°, 193 nm . . . . . . . . . .  102Turning Mirror 45°, 248 nm . . . . . . . . . .  102Turning Mirror 45°, 308 nm . . . . . . . . . .  102Window 0°, 193 nm. . . . . . . . . . . . . . . .  102Window 0°, 248 nm. . . . . . . . . . . . . . . .  103Window 0°, 308 nm. . . . . . . . . . . . . . . .  103

Turning Mirror
45°

Excimer laser
Window 0°

For optics not specified here, please visit www.layertec.de,contact us at info@layertec.de or call us at + 49 (0)36453 744 0.

Turning Mirror 45°, 193 nm

Turning Mirror 45°, 308 nm

s
u
R [%]

p

wavelength [nm]
170

175

180

185

190

195

200

205

210

Substrate Dimensions

No.

Imperfections Item #Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 5.0 mm
50 × 27 mm | t 3.0 mm

B4 f
C1 f
O1 f

5/ 4 x 0.063
5/ 5 x 0.063
5/ 5 x 0.063

215

220

Price

107229160821
160820

454 €
906 €
768 €

Turning Mirror 45°, 248 nm

u
R [%]

p

wavelength [nm]
230

240

p

wavelength [nm]
275

285

295

305

Substrate Dimensions

No.

Imperfections Item #Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 6.35 mm
50 × 27 mm | t 6.35 mm

B4
C2
O2

5/ 2 x 0.04
5/ 3 x 0.063
5/ 2 x 0.063

250

260

270

Substrate Dimensions

No.

Imperfections Item #Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 6.35 mm
50 × 27 mm | t 6.35 mm

B4
C2
O2

5/ 2 x 0.04
5/ 3 x 0.063
5/ 2 x 0.063

160804160803160806

280

Price

282 €
772 €
585 €

100.0
99.5
99.0
98.5
98.0
97.5
97.0
96.5
96.0
95.5
95.0

325

335

345

Price

160801160802160807

282 €
772 €
585 €

S2

S1

CaF2
Fused Silica

wavelength [nm]
170

175

180

185

190

195

Substrate Dimensions

No.

Imperfections Item #Ø 25.0 mm | t 3.0 mm

B3 f

5/ 2 x 0.063

200

205

210

Substrate Dimensions

No.

Imperfections Item #Ø 25.0 mm | t 3.0 mm

B3 d

5/ 2 x 0.063

160702

215

220

Price

423 €

Coating on CaF₂

Coating on Fused Silica

102

315

S2+S1: Coating 113604 on CaF₂ 193 nm excimer grade
S2+S1: Coating 120805 on Fused Silica 193 nm excimer grade
T % 193
CaF2nm) < 0.25
T % FS%AR (0°,

s

220

s
u

Window 0°, 193 nm

Coating 159573
HRu (45°, 248 nm) > 99.5 %HRs (45°, 248 nm) > 99.7 %HRp (45°, 248 nm) > 99.0 %
100
99
98
97
96
95
94
93
92
91
90

100
99
98
97
96
95
94
93
92
91
90

T [%]

100
98
96
94
92
90
88
86
84
82
80

Coating 159576
HRu (45°, 308 nm) > 99.5 %HRs (45°, 308 nm) > 99.9 %HRp (45°, 308 nm) > 99.5 %R [%]Coating 113257 on CaF₂ UV-grade
HRu (45°, 193 nm) > 95 %HRs (45°, 193 nm) > 97 %HRp (45°, 193 nm) > 93 %

160701

Price

300 €

Standard Items from Stock
Excimer Lasers [193 nm, 248 nm, 308 nm]

Window 0°, 248 nm
S2+S1: Coating 127980 on Fused Silica 248 nm excimer grade
AR (0°, 248 nm) < 0.25 %
S2

S1

T [%]

100
99
98
97
96
95
94
93
92
91
90

wavelength [nm]
200

210

220

230

240

250

260

270

280

Substrate Dimensions

No.

Imperfections Item #Ø 25.0 mm | t 3.05 mm

B3 c

5/ 1 x 0.04

160700

290

300

Price

264 €

Window 0°, 308 nm
S2+S1: Coating 120555 on Fused Silica 248 nm excimer grade
AR (0°, 308 nm) < 0.25 %
S2

S1

T [%]

100
99
98
97
96
95
94
93
92
91
90

wavelength [nm]
250

265

280

295

310

325

340

355

370

Substrate Dimensions

No.

Imperfections Item #Ø 25.0 mm | t 3.05 mm

B3 c

5/ 1 x 0.04

160699

385

400

Price

264 €

103

Standard Items from Stockfs-Laser [TiSa, up to 150 nm bandwidth]

fs-Laser [TiSa, up to 150 nm bandwidth]
Pump
MirrorPump
Mirrorpump
laser

crystal

Laser
MirrorChirpedMirrorChirpedMirrorLaser
Mirror

OC
wedge
Turn

Chirped Mirror Pairon request

ing
M
22.5 irror°

on request

Laser Mirror 0° . . . . . . . . . . . . . . . . . . .  104Laser Mirror 0°, high power. . . . . . . . . .  104Pump Mirror 5°. . . . . . . . . . . . . . . . . . . .  105Turning Mirror 22.5°. . . . . . . . . . . . . . . .  105Turning Mirror 45° . . . . . . . . . . . . . . . . .  105Turning Mirror 45°, p-pol.. . . . . . . . . . . .  105Turning Mirror 45°, high power . . . . . . .  106Separator 0°, 750 – 850 / 360 – 450 nm . .  106Separator 45°, 760 – 850 / 350 –450 nm. .  106Laser Mirror 0 – 45° . . . . . . . . . . . . . . . .  106Chirped Mirror 5° . . . . . . . . . . . . . . . . .  107Chirped Mirror Pair 5°, -40 fs2 . . . . . . . .  107Chirped Mirror Pair 5°, -80 fs2 . . . . . . . .  107Chirped Mirror Pair 5°, -110 fs2 . . . . . . . .  107Beamsplitter 45°, s-pol. . . . . . . . . . . . . .  108Beamsplitter 45°, p-pol.. . . . . . . . . . . . .  108Window 0°. . . . . . . . . . . . . . . . . . . . . . .  108

Pol

ari
75° zerBeamsplitter

Laser Mirror 0°

Laser Mirror 0°, high power

Coating 139691
HRs,p (0 – 10°, 725 – 875 nm) > 99.9 %| GDD-Rs,p (0–10°, 725 – 875 nm) | < 50 fs2

wavelength [nm]
700

750

800

850

900

950

wavelength [nm]
700

100
80
60
40
20
0
-20
-40
-60
-80
-100
700

750

800

850

900

950

GDD-R [fs2]wavelength [nm]
720

740

760

780

800

820

LIDT
6/ 0.4 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 80 µm
6/ 2 J/cm2; 800 nm; 70 fs; 10 Hz; Ø 700 µm

104

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
650

R [%]

R [%]

Coating 140876
HRs,p (0 – 10°, 750 –  850 nm) > 99.5%| GDD-Rs,p (0 –  10°, 750 –  850 nm) | < 60 fs²

GDD-R [fs2]

100
80
60
40
20
0
-20
-40
-60
-80
-100
700

Laser
Mirror0-45°

Turning
Mirror45°

For optics not specified here, please visit www.layertec.de,contact us at info@layertec.de or call us at + 49 (0)36453 744 0.

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
650

Window

840

860

880

900

WRCP Budapest
HZDR Dresden

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm

A4
B4
C3

5/ 1 x 0.04
5/ 3 x 0.04
5/ 4 x 0.063

140189140136140188

Price

100 €
138 €
468 €

wavelength [nm]
720

740

760

780

800

820

LIDT
6/ 1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 80 µm
6/ 2 J/cm2; 800 nm; 30 fs; 10 Hz; Ø 700 µm

840

860

880

900

WRCP Budapest
HZDR Dresden

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5/ 2 x 0.025
5/ 1 x 0.063
5/ 3 x 0.063
5/ 1 x 0.063

141855141856141857141861

Price

84 €
114 €
396 €
144 €

Standard Items from Stockfs-Laser [TiSa, up to 150 nm bandwidth]

Pump Mirror 5°

Turning Mirror 45°

S2

R [%]

550

600

650

700

750

800

850

900

950

wavelength [nm]
720

740

760

780

800

820

840

LIDT
6/ 0.4 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 80 µm

860

880

900

WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 | t 6.35 | CC 38
Ø 12.7 | t 6.35 | CC 50
Ø 12.7 | t 6.35 | CC 75Ø 12.7 | t 6.35 | CC 100
Ø 12.7 | t 6.35 | CC 125

R2
R3
R4
R5
R6

5/ 1 x 0.04
5/ 1 x 0.04
5/ 1 x 0.04
5/ 1 x 0.04
5/ 1 x 0.04

142340142341
142342142343142345

Price

195 €
176 €
176 €
162 €
162 €

s

wavelength [nm]
700

750

800

850

900

950

s
p
wavelength [nm]
720

740

760

780

800

820

840

LIDT
6/ 0.4 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 80 µm

860

880

900

WRCP Budapest

Substrate Dimensions

No.

Imperfections Item #Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
Ø 76.2 mm | t 12.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
D1
K2

5/ 1 x 0.04
5/ 3 x 0.04
5/ 4 x 0.063
5/ 7 x 0.063
5/ 3 x 0.04

Price140193140194140195146559141876

100 €
138 €
468 €
984 €
174 €

Turning Mirror 45°, p-pol.
Coating 139711
HRp (45°, 725 – 875 nm) > 99.8 %GDD-Rp (45°, 725 – 875 nm) = -40 (±30) fs2

Turning Mirror 22.5°

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
675
100
80
60
40
20
0
-20
-40
-60
-80
-100
700

R [%]

R [%]

Coating 139710
HRs,p (22.5°, 725 – 875 nm) > 99.9 %| GDD-Rs,p (22.5°, 725 – 875 nm) | < 75 fs2
100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
650
100
80
60
40
20
0
-20
-40
-60
-80
-100
700

100
80
60
40
20
0
-20
-40
-60
-80
-100
700

p

GDD-Rs,p [fs2]

S2

GDD-R [fs2]

100
80
60
40
20
0
-20
-40
-60
-80
-100
700

wavelength [nm]
500

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
650

p

s

wavelength [nm]
710

740

770

800

830

860

890

920

950

GDD-R [fs2]

680

s
p
wavelength [nm]
720

740

760

780

800

820

LIDT
6/ 2 J/cm2; 800 nm; 70 fs; 10 Hz; Ø 700 µm
6/ 0.4 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 80 µm

840

860

880

HZDR Dresden
WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm

A4
B4
C3

5/ 1 x 0.04
5/ 3 x 0.04
5/ 4 x 0.063

140190140191140192

Price

108 €
150 €
498 €

900

p
wavelength [nm]
725

775

825

875

925

GDD-Rp [fs2]

100
90
80
70
60
50
40
30
20
10
0
450

Coating 139693
HRs,p (45°, 740 – 860 nm) > 99.9 %| GDD-Rs,p (45°, 740 – 860 nm) | < 75 fs²

R [%]S2: Coating 140872
HRs,p (0 – 10°, 725 – 875 nm) > 99.9 %Rs,p (0 – 10°, 500 – 545 nm) < 2 %| GDD-Rs,p (0 – 10°, 725 –  875 nm) | < 40 fs²
S1: Coating 140875
ARs,p (0 – 10°, 500 – 545 nm) < 0.2 %pwavelength [nm]
720

740

760

780

800

820

840

860

880

900

LIDT
6/ 0.4 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
WRCP Budapest
6/ 0.1 J/cm2; 800 nm; 128 fs; 4.3 MHz; Ø 15 µm WRCP Budapest
Substrate Dimensions

No.

Imperfections

Item #PriceØ 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
Ø 76.2 mm | t 12.5 mm

A4
B4
C3
D1

5/ 1 x 0.04
5/ 3 x 0.04
5/ 4 x 0.063
5/ 7 x 0.063

140208140209146565146566

138 €
246 €
732 €
1 488 €

105

Standard Items from Stockfs-Laser [TiSa, up to 150 nm bandwidth]

Turning Mirror 45°, high power

Separator 45°, 760 – 850 / 350 –450 nm

pswavelength [nm]

700

750

800

850

900

950

150

50
0
-50

GDD-Rs,p [fs2]

100

p

-100
-150
700

s
wavelength [nm]

720

740

760

780

800

820

840

LIDT
6/ 0.9 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 80 µm
6/ 1.0 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm
6/ 3 J/cm2; 800 nm; 30 fs; 10 Hz; Ø 830 µm

860

880

900

WRCP Budapest
WRCP Budapest
HZDR Dresden

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
Ø 76.2 mm | t 12.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
D1
K2

5/ 2 x 0.025
5/ 1 x 0.063
5/ 3 x 0.063
5/ 3 x 0.1
5/ 1 x 0.063

140963141238141239146567141870

84 €
114 €
396 €
864 €
144 €

10
9
8
7
6
5
4
3
2
1
0
320

wavelength [nm]
720

740

760

780

800

820

840

860

880

720

740

760

780

800

820

840

860

900

920
S2

s
p
wavelength [nm]
340

360

380

400

420

440

460

480

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 2 x 0.04

104991

500

Price

354 €

Laser Mirror 0 – 45°
Coating 139943
Ag + MultilayerHRs,p (0 – 45°, 725 – 875 nm) > 98 %R 0 (%) (45°, 725
R p–(%)s (%)| GDD-Rs,p875 nm) | <R40
fs²
0°
45°
s

98.5
98.0
97.5
97.0
96.5
96.0
95.5
95.0
650

R [%]

R [%]

wavelength [nm]
880

900

920
S2

45°

p

wavelength [nm]
700

100
80
60
40
20
0
-20
-40
-60
-80
-100
650

750

800

850

900

950

0°
45°p
45°

s

wavelength [nm]
700

750

800

900

850

950

LIDT
6/ 0.9 J/cm²; 800 nm; 40 fs; 1 kHz; Ø 80 µm; AOI 0° WRCP Budapest

R [%]

106

98.8
98.6
98.4
98.2
98.0
700

GDD-Rs,p [fs2]

S2

10
9
8
7
6
5
4
3
2
1
0
320

s

100.0
99.5
99.0

S2: Coating 160927
HR (0°, 750 – 850 nm) > 99.9 %R (0°, 360 – 440 nm) < 5 %| GDD-R (0°, 750 – 850 nm) | < 40 fs²
S1: Coating 160929
AR (0°, 360 – 440 nm) < 0.5 %

98.8
98.6
98.4
98.2
98.0
700

S2

p

Price

Separator 0°, 750 – 850 / 360 – 450 nm

100.0
99.8
99.6
99.4
99.2
99.0

100.0
99.8
99.6
99.4
99.2
99.0

R [%]

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
650

S2: Coating 113728
HRu (45°, (760 – 850 nm) ±5 nm) > 99.9 %Ru (45°, (360 – 440 nm) ±5 nm) < 2 %| GDD-Ru (45°, 760 – 850 nm) | < 40 fs²| GDD-Tu (45°, 360 – 440 nm)| < 40 fs²
S1: Coating 124879
ARu (45°, 350 – 450 nm) < 0.7 %R [%]Coating 140881
HRs (45°, 730 – 870 nm) > 99.8 %HRp (45°, 760 – 840 nm) > 99.5 %| GDD-Rs,p (45°, 760 – 840 nm) | < 80 fs²

wavelength [nm]
340

360

380

400

420

440

460

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 2 x 0.04

160934

480

500

Price

342 €

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5 / 1 x 0.04
5 / 3 x 0.04
5 / 4 x 0.063
5 / 3 x 0.04

140211140213140214141878

Price

100 €
132 €
444 €
168 €

Standard Items from Stockfs-Laser [TiSa, up to 150 nm bandwidth]

Chirped Mirror 5°

Chirped Mirror Pair 5°, -80 fs2

Coating 140884
HRs,p (0 – 10°, 725 – 875 nm) > 99.9 %GDD-Rs,p (0 – 10°, 725 – 875 nm) = - 40 (±10) fs²

R [%]

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
500

wavelength [nm]
730

100
80
60
40
20
0
-20
-40
-60
-80
-100
680

780

830

880

930

650

700

750

800

850

900

730

780

830

880

930

-100

WRCP Budapest
WRCP Budapest

Imperfections

Item #

A4
B4

5/ 1 x 0.04
5/ 4 x 0.04

141243141245

Price

366 €
570 €

wavelength [nm]
750

800

850

LIDT
6/ 0.1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

WRCP Budapest
WRCP Budapest

Substrate Dimensions

Imperfections

Item #Price

5/ 1 x 0.04
5/ 4 x 0.04
5/ 3 x 0.04

141887141888141891834 €
1 220 €
1 730 €

No.

Coating 141570 + 141571
HRs,p (0 – 10°, 725 – 875 nm) > 99.8 %GDD-Rs,p (0 – 10°, 725 – 875 nm) = -110 (±50) fs²
to compensate 3 mm Fused Silica per bounce (average)

88
409
g1
0
099
14

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
500

coating 141571
coating 141570

wavelength [nm]
550

600

650

700

750

800

850

900

950

900

Chirped Mirror Pair 5°, -110 fs2

coa
tin
coat
ing

R [%]

700

Ø 12.7 mm | t 6.35 mm A4
Ø 25.0 mm | t 6.35 mm B440 x 10 mm² | t 12.5 mm N1

Chirped Mirror Pair 5°, -40 fs2
Coating 140988 + 140990
HRs,p (0 – 10°, 725 – 875 nm) > 99.8 %GDD-Rs,p (0 – 10°, 725 – 875 nm) = - 40 (±20) fs²
to compensate 1 mm Fused Silica per bounce (average)

1000

-150
-200
650

No.

950

coating
141561
coating 1415
60

wavelength [nm]GDD-R [fs2]GDD-R [fs2]0-50

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

1000

wavelength [nm]
550

600

650

700

750

800

850

900

950

1000

100
50

coating
1409900

GDD-R [fs2]GDD-R [fs2]

600

50

Substrate Dimensions

100
80
60
40
20
0
-20
-40
-60
-80
-100
600

wavelength [nm]
550

100

LIDT
6/ 0.2 J/cm2; 800 nm; 40 fs; 1 kHz Ø 80 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
500

g 141560
coating 141561
coatin

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
680

Coating 141560 + 141561
HRs,p (0 – 10°, 725 – 875 nm) > 99.9 %GDD-Rs,p (0 – 10°, 725 – 875 nm) = -80 (±40) fs²
to compensate 2.35 mm Fused Silica per bounce (average)-50

coating
140988650

wavelength [nm]
700

750

800

850

900

950

WRCP Budapest
WRCP Budapest

Substrate Dimensions

Imperfections

Item #Price

5/ 1 x 0.04
5/ 4 x 0.04
5/ 3 x 0.04

141882141884141886804 €
1 180 €
1 670 €

Ø 12.7 mm | t 6.35 mm A4
Ø 25.0 mm | t 6.35 mm B440 x 10 mm² | t 12.5 mm N1

-150
-200
650

LIDT
6/ 0.2 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm
No.

coating
141571-100

coating 141570
700

wavelength [nm]
750

800

850

900

LIDT
6/ 0.1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

WRCP Budapest
WRCP Budapest

Substrate Dimensions

Imperfections

Item #Price

5/ 1 x 0.04
5/ 4 x 0.04
5/ 3 x 0.04

141920141919141918864 €
1 250 €
1 790 €

No.

Ø 12.7 mm | t 6.35 mm A4
Ø 25.0 mm | t 6.35 mm B440 x 10 mm² | t 12.5 mm N1

107

Standard Items from Stockfs-Laser [TiSa, up to 150 nm bandwidth]

Beamsplitter 45°, s-pol.

Window 0°

S2: Coating 141113
PRs (45°, 725 –  875 nm) = 50 (±2) %| GDD-Rs (725 –  875 nm) | < 5 fs²
S1: Coating 141114
ARs (45°, 725 – 875 nm) < 0.5 %S2+S1: Coating 140890
ARs,p (0 – 15°, 725 –  875 nm) < 0.2 %

65
R [%]

60
55
50
45
40
35

wavelength [nm]

30

650

5
4
3
2
1
0
-1
-2
-3
-4
-5

700

750

800

850

900

950

GDD-Rs / GDD-Ts[fs2]

S2

GDD-RsGDD-Tswavelength [nm]
650

700

750

800

850

900

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 0.5 mm
Ø 25.0 mm | t 1.0 mm
Ø 25.0 mm | t 3.05 mm

B1
B2
B3

5/ 4 x 0.04
5/ 3 x 0.04
5/ 3 x 0.04

141512141511141502

950

Price

348 €
324 €
264 €

Beamsplitter 45°, p-pol.
S2: Coating 141122
PRp (45°, 725 – 875 nm) = 50 (±2) %| GDD-Rp (45°, 725 – 875 nm) | < 20 fs²
S1: Coating 141121
ARp (45°, 725 – 875 nm) < 0.2 %
S2

70
65
60
R [%]

55
50
45
40
35
30

wavelength [nm]
650

700

750

800

850

900

950
S2

20
10
0
-10
-20

GDD-Rp / GDD-Tp[fs2]

30

-30
650

108

GDD-TpGDD-Rpwavelength [nm]
700

800

750

900

850

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 0.5 mm
Ø 25.0 mm | t 1.0 mm
Ø 25.0 mm | t 3.05 mm

B1
B2
B3

5/ 4 x 0.04
5/ 3 x 0.04
5/ 3 x 0.04

141513141509141506

950

Price

348 €
324 €
264 €

S2

S1

T [%]

S2

70

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

wavelength [nm]
650

700

750

800

850

LIDT
6/ 0.4 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.5 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

900

950

WRCP Budapest
WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 1.0 mm
Ø 25.0 mm | t 3.05 mm

B2
B3

5/ 3 x 0.04
5/ 3 x 0.04

141514141519

Price

216 €
156 €

Standard Items from Stockfs-Laser [TiSa, 300 nm bandwidth]

fs-Laser [TiSa, 300 nm bandwidth]
Pump
MirrorPump
MirrorLaser Mirror 0°. . . . . . . . . . . . . . . . . . . .  109Pump Mirror Pair 0° . . . . . . . . . . . . . . . .  109Turning Mirror 22.5°. . . . . . . . . . . . . . . .  110Turning Mirror 45°, p-pol.. . . . . . . . . . . .  110Turning Mirror 45°, s-pol.. . . . . . . . . . . .  110Turning Mirror 45°. . . . . . . . . . . . . . . . .  110Laser Mirror 0 –45°. . . . . . . . . . . . . . . . .  111Chirped Mirror Pair 5°. . . . . . . . . . . . . . .  111Beamsplitter 45°, p-pol.. . . . . . . . . . . . .  111Beamsplitter 45°, s-pol. . . . . . . . . . . . . .  112Polarizer 75°. . . . . . . . . . . . . . . . . . . . . .  112Window 0°. . . . . . . . . . . . . . . . . . . . . . .  112

crystal

Laser
MirrorChirpedMirrorChirpedMirrorLaser
Mirror
Turn

wedge

ing
M
22.5 irror°

wedge
Polarizer
75°

Laser
Mirror
0-45°

Window

Turning
Mirror45°

Beamsplitter45°

For optics not specified here, please visit www.layertec.de, contact us at info@layertec.de or call us at + 49 (0)36453 744 0.

Laser Mirror 0°

Pump Mirror Pair 0°

Coating 141318
HRs,p (0 – 10°, 670 – 970 nm) > 99.9 %GDD-Rs,p (0 – 10°, 670 – 970 nm) = -50 (±75) fs²
to compensate 1.4 mm Fused Silica per bounce (average)

100

700

750

800

850

900

950

1000

1050

-200
-300
-400
-500
580

wavelength [nm]
635

690

745

800

855

LIDT
6/ 0.1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

910

965

1020

WRCP Budapest
WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B4

5 / 1 x 0.04
5 / 4 x 0.04

142010142012

Price

348 €
552 €

200
160
120
80
40
0
-40
-80

coating 136768

S2

coating 136769

wavelength [nm]
540

600

660

720

780

840

900

960

1020

1080
S2

GDD-R [fs2]650

GDD-R [fs2]

500
400
300
200
100
0
-100

wavelength [nm]
600

90
80
70
60
50
40
30
20
10
0
480

R [%]

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
550

S2: Coating 136768 + 136769
HRs,p (0 – 10°, 670 – 970 nm) > 99.8%
Rs,p (0 – 10°, 510 – 535 nm) < 10 %GDD-Rs,p (0 – 10°, 680 – 960 nm) = -50 (±150) fs²
to compensate 1.2 mm Fused Silica per bounce (average)
S1: Coating 140875
ARs,p (0 – 10°, 500 – 545 nm) < 0.2 %

-120
-160
-200
600

coating
136769coating
136768wavelength [nm]
650

700

800

750

850

900

950

1000

LIDT
6/ 0.1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

WRCP Budapest
WRCP Budapest

Substrate Dimensions [mm]No.

Imperfections

Item #

Ø 12.7 | t 6.35 | CC 38
Ø 12.7 | t 6.35 | CC 50
Ø 12.7 | t 6.35 | CC 75Ø 12.7 | t 6.35 | CC 100
Ø 12.7 | t 6.35 | CC 125

R2
R3
R4
R5
R6

5 / 1 x 0.04
5 / 1 x 0.04
5 / 1 x 0.04
5 / 1 x 0.04
5 / 1 x 0.04

142351142350142349142348142347

Price

930 €
890 €
890 €
864 €
864 €

109

Standard Items from Stockfs-Laser [TiSa, 300 nm bandwidth]

Turning Mirror 22.5°

Turning Mirror 45°, s-pol.

Coating 141503
HRs,p (22.5°, 670 – 970 nm) > 99.8 %GDD-Rs,p (22.5°, 670 – 970 nm) = -200 … + 200 fs²

R [%]

s

wavelength [nm]
680

730

780

830

880

930

980

1030

1080

reflected beam, AOI 22.5°

GDD-Rs,p [fs2]

500
400
300
200
100
0
-100

p

-200
-300
-400
-500
650

p s

wavelength [nm]
690

730

770

810

850

890

930

LIDT
6/ 0.1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

970

1010

1050

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm

A4
B4
C3

5 / 1 x 0.04
5 / 3 x 0.04
5 / 4 x 0.063

141584141567141925

150 €
276 €
792 €

30
0
-30
-60

830

870

910

950

670

710

750

790

830

870

910

950

740

780

820

860

900

940

980

1020

1060

wavelength [nm]
740

780

820

860

900

940

1030

990

1030

WRCP Budapest
WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #PriceØ 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
Ø 76.2 mm | t 12.5 mm

A4
B4
C3
D1

5 / 1 x 0.04
5 / 3 x 0.04
5 / 4 x 0.063
5 / 7 x 0.063

141586141578141928146570

144 €
264 €
768 €
1 590 €

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
550
2000
1600
1200
800
400
0

700

990

wavelength [nm]

p

R [%]

wavelength [nm]
700

LIDT
6/ 0.1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

110

790

Coating 141522
HRs,p (45°, 670 – 970 nm) > 99.7 %| GDD-Rs,p (45°, 670 – 970 nm) | < 1 500 fs²

R [%]

-90
-120
-150
660

750

Turning Mirror 45°

GDD-Rp [fs2]

150
120
90
60

710

LIDT
6/ 0.1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

Price

Coating 141520
HRp (45°, 670 – 970 nm) > 99.8 %GDD-Rp (45°, 670 – 970 nm) = -200 … 0 fs²

98.8
98.6
98.4
98.2
98.0
660

-200
-300
-400
-500
630

WRCP Budapest
WRCP Budapest

Turning Mirror 45°, p-pol.

100.0
99.8
99.6
99.4
99.2
99.0

500
400
300
200
100
0
-100

wavelength [nm]
670

980

1020

1060

WRCP Budapest
WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #PriceØ 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
Ø 76.2 mm | t 12.5 mm

A4
B4
C3
D1

5 / 1 x 0.04
5 / 3 x 0.04
5 / 4 x 0.063
5 / 7 x 0.063

141585141568141926146569

150 €
276 €
792 €
1 620 €swavelength [nm]
650

750

850

950

1050

1150

reflected beam, AOI 45°p
GDD-Rs,p [fs2]

98.8
98.6
98.4
98.2
98.0
630

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
630

GDD-Rs [fs2]

R [%]

100.0
99.8
99.6
99.4
99.2
99.0

Coating 141507
HRs (45°, 670 – 970 nm) > 99.9 %GDD-Rs (45°, 670 – 970 nm) = -200 … + 200 fs²

-400
-800
-1200
-1600
-2000
650

s

wavelength [nm]
700

750

800

850

900

LIDT
6/ 0.1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

950

1000

1050

WRCP Budapest
WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm

A4
B4
C3

5 / 1 x 0.04
5 / 3 x 0.04
5 / 4 x 0.063

141587141579141930

Price

150 €
276 €
792 €

Standard Items from Stockfs-Laser [TiSa, 300 nm bandwidth]

Laser Mirror 0 –45°

Chirped Mirror Pair 5°
Coating 137180 + 137181
HRs,p (0 – 10°, 670 – 970 nm) > 99.8 %GDD-Rs,p (0 – 10°, 680 – 960 nm) = -50 (±150) fs²
to compensate 1.4 mm Fused Silica per bounce (average)

Coating 141523
Ag + MultilayerHRs,p (0 – 45°, 670 – 970 nm) > 97 %| GDD-Rs,p (0 – 45°, 670 – 970 nm) | < 50 fs²
for application outside the resonator

700

750

800

850

900

950

0°

1000

45°p
45°s

wavelength [nm]
650

700

750

800

850

LIDT
6/ 0.4 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 1.5 J/cm2; 800 nm; 30 fs; 10 kHz; Ø 700 µm

900

950

1000

R [%]

200
160
120
80
40
0
-40
-80

-120
-160
-200
600

WRCP Budapest
HZDR Dresden

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5 / 1 x 0.04
5 / 3 x 0.04
5 / 4 x 0.063
5 / 3 x 0.04

142001142002142003142005GDD-R [fs2]R [%]wavelength [nm]650

GDD-Rs,p [fs2]

100
80
60
40
20
0
-20
-40
-60
-80
-100
600

45°p

Price

105 €
138 €
462 €
177 €

coating 137180°s137181
coating45

wavelength [nm]
650

700

750

800

850

900

950

1000

1050

1100

coating
137181
coating
137180wavelength [nm]
700

650

750

800

900

850

950

1000

LIDT
6/ 0.1 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.25 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

WRCP Budapest
WRCP Budapest

Substrate Dimensions

Imperfections

Item #Price

5/ 1 x 0.04
5/ 4 x 0.04
5/ 3 x 0.04

141931141933141934834 €
1 220 €
1 730 €

No.

Ø 12.7 mm | t 6.35 mm A4
Ø 25.0 mm | t 6.35 mm B440  x 10 mm² | t 12.5 mm N1

Beamsplitter 45°, p-pol.
S2: Coating 141555
PRp (45°, 670 – 970 nm) = 50 (±5) %| GDD-Rp (45°, 670 – 970 nm) | < 10 fs²
S1: Coating 141556
ARp (45°, 670 – 970 nm) < 0.2 %
S2

70
65
60
55
50

R [%]

0°

98.5
98.0
97.5
97.0
96.5
96.0
95.5
95.0
600

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
600

45
40
35
30
550

wavelength [nm]
600

650

700

750

800

850

900

950

1000

S2

50
40
30
20
10
0
-10
-20

1050

GDD-Rp [fs2]

100.0
99.5
99.0

-30
-40
-50
600

wavelength [nm]
650

700

750

800

850

900

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 1 mm
Ø 25.0 mm | t 3.05 mm

B2
B3

5 / 3 x 0.04
5 / 3 x 0.04

141975141978

950

1000

Price

348 €
288 €

111

Standard Items from Stockfs-Laser [TiSa, 300 nm bandwidth]

Beamsplitter 45°, s-pol.

Window 0°

S2: Coating 141558
PRs (45°, 670 – 970 nm) = 50 (±5) %| GDD-Rs (45°, 670 – 970 nm) | < 5 fs²
S1: Coating 141557
ARs (45°, 670 – 970 nm) < 0.7 %S2+S1: Coating 141528
ARs,p (0 – 15°, 670 – 970 nm) < 0.25 %

98.8
98.6
98.4
98.2
98.0
575

wavelength [nm]
600

650

700

750

800

850

900

950

1000

1050

20

S2

GDD-Rs[fs2]

16
12
8
4
0

-4
-8
-12
-16
-20
550

wavelength [nm]
700

750

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 1 mm
Ø 25.0 mm | t 3.05 mm

B2
B3

5 / 3 x 0.04
5 / 3 x 0.04

141977141979

600

650

800

850

900

950

1000

1050

Price

348 €
288 €

Polarizer 75°
S2+S1: Coating 141529
TFP (75°, 670 – 970 nm) Rs > 80 % Rp < 1 %| GDD-Rs (75°, 670 – 970 nm) | < 20 fs²| GDD-Tp (75°, 680 – 960 nm) | < 5 fs²

Rs

75°

S2
S1
Tp

Polarizer
Special item forclean separationof p-pol. light.
S2

100

)
×10
oom
p (z

p
wavelength [nm]
700

750

800

850

900

950

-10
-20
-30
-40

GDD-Rs[fs2] /GDD-Tp[fs2]

10
0

-50
650

112

1000
S2

50
40
30
20

S1

s

R [%]

90
80
70
60
50
40
30
20
10
0
650

S2

S1

75°)
-Tp (
GDD
(75°)
GDD-Rswavelength [nm]
700

750

800

850

900

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 1 mm
Ø 25.0 mm | t 3.05 mm

B2
B3

5 / 3 x 0.04
5 / 3 x 0.04

142013142014

950

1000

Price

438 €
378 €

S1

T [%]

S2

R [%]

60
58
56
54
52
50
48
46
44
42
40
550

100.0
99.8
99.6
99.4
99.2
99.0

wavelength [nm]
625

675

725

775

825

875

LIDT
6/ 0.4 J/cm2; 800 nm; 40 fs; 1 kHz; Ø 15 µm
6/ 0.5 J/cm2; 800 nm; 128 fs; 1 kHz; Ø 15 µm

925

975

1025

1075

WRCP Budapest
WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 1 mm
Ø 25.0 mm | t 3.05 mm

B2
B3

5 / 3 x 0.04
5 / 3 x 0.04

141588141590

Price

234 €
174 €

Standard Items from Stock
ps/fs-Laser [1030–1040 nm]

ps/fs-Laser [1030–1040 nm]
Pump
Mirror

Separator 22.5°

pump
laser

Laser Mirror 0°. . . . . . . . . . . . . . . . . . . .  113Pump Mirror 0°, 800 – 982 nm . . . . . . . .  113Pump Mirror 0°, 960 – 982 nm . . . . . . . .  114Turning Mirror 45°. . . . . . . . . . . . . . . . .  114GTI-Mirror 5°, 1 030 nm, -250 fs2 . . . . . .  114GTI-Mirror 5°, 1 030 nm, -550 fs2 . . . . . .  114GTI-Mirror 5°, 1 030 nm, -1 000 fs2 . . . . .  115GTI-Mirror 5°, 1 040 nm, -250 fs2 . . . . . .  115GTI-Mirror 5°, 1 040 nm, -550 fs2 . . . . . .  115GTI-Mirror 5°, 1 040 nm, -1 000 fs2 . . . . .  115Separator 22.5° . . . . . . . . . . . . . . . . . . .  116Thin Film Polarizer 45°, 1 030 nm . . . . . .  116Thin Film Polarizer 45°, 1 042 nm . . . . . .  116Thin Film Polarizer 56°, 1 030 nm . . . . . .  116Thin Film Polarizer 56°, 1 042 nm . . . . . .  116Window 0°. . . . . . . . . . . . . . . . . . . . . . .  116

LaserMirror
crystalTurning
Mirror45°

GTIMirror

OC

Laser
MirrorWindow
TFP

Laser Mirror 0°

Pump Mirror 0°, 800 – 982 nm

100
80
60
40
20
0
-20
-40
-60
-80
-100

1000

1050

1100

1150

1200

wavelength [nm]
980

990

1000

1010

1020

1030

1040

LIDT
6/ 3 J/cm2; 1030 nm; 10 ps; 1 kHz; Ø 50 µm

1050

1060

1070

1080

LIDARIS Vilnius

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5 / 1 x 0.04
5 / 3 x 0.04
5 / 4 x 0.063
5 / 3 x 0.04

141246141248141249139564

Price

126 €
204 €
660 €
270 €

R [%]

950

100
90
80
70
60
50
40
30
20
10
0
750

1000
800
600
400
200
0
-200
-400
-600
-800
-1000
1000

S2
100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1000

1010

1020

1030

1040

1050

1060

wavelength [nm]
800

850

900

950

1000

1050

1100

1150
S2

GDD [fs2]

wavelength [nm]900

GDD [fs2]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

S2: Coating 141171
HR (0°, 1 030  – 1 040 nm) > 99.9 %R (0°, 800  –  982 nm) < 5 %GDD-R (0°, 1 030 –1 040 nm) = 300 (±300) fs²
cut on/off R (0°) = T (0°) = 50 % at 995 (±10) nm
AOI 0° → 10° : shift cut on/off-wavelength -5 nm
S1: Coating 141174
AR (0°, 800 – 1 000 nm) < 0.5 %R [%]Coating 139374
HRs,p (0 – 10°, 1 030 – 1 042 nm) > 99.99 %| GDD-Rs,p (0 – 10°, 1 030 – 1 042 nm) | < 20 fs2

wavelength [nm]
1010

1020

1030

1040

1050

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B4

5 / 1 x 0.04
5 / 4 x 0.04

141951141530

1060

Price

378 €
552 €

113

Standard Items from Stock
ps/fs-Laser [1030–1040 nm]

Pump Mirror 0°, 960 – 982 nm

GTI-Mirror 5°, 1 030 nm, -250 fs2

S2
100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1000

1010

1020

1030

1040

1050

wavelength [nm]
960

970

980

990

1000

1010

1020

1030

1040

1050

200

S2

150
50
0
-50

GDD [fs2]

100

-100
-150

wavelength [nm]

-200
1010

1020

1030

1040

1050

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B4

5 / 1 x 0.04
5 / 4 x 0.04

141952141525

Price

414 €
612 €

1000

1050

1100

1150

1200

GDD [fs2]

950

114

s
p
wavelength [nm]
1010

1020

1030

1040

R [%]

1000

1050

1100

1150

10°

1200

0°

wavelength [nm]
980

990

1000

1010

1020

1030

1040

1050

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B45/ 1 x 0.04
5/ 4 x 0.04

141250141251

1070

1080

Price

372 €
576 €

GTI-Mirror 5°, 1 030 nm, -550 fs2
Coating 141149
HRs,p (0 – 10°, 1 030 nm) > 99.95 %GDD-Rp (0 – 10°, 1 030 nm) = -550 (±100) fs²

R [%]

R [%]

p
s
wavelength [nm]
900

950

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
900

Coating 141317
HRs,p (45°, 1 030 – 1 040 nm) > 99.9 %| GDD-Rs,p (45°, 1 030 – 1 040 nm) | < 20 fs²

50
40
30
20
10
0
-10
-20
-30
-40
-50
1000

0
-50
-100
-150
-200
-250
-300
-350
-400
-450
-500

wavelength [nm]
900

1060

Turning Mirror 45°

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

1050

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5/ 1 x 0.04
5/ 3 x 0.04
5/ 4 x 0.063
5/ 3 x 0.04

141569141501141572141573

1070

1080

Price

100 €
142 €
516 €
180 €

0
-100
-200
-300
-400
-500
-600
-700
-800
-900
-1000
980

wavelength [nm]
950

1000

1050

1100

1150

10°

1200

0°

GDD [fs2]

R [%]

100
90
80
70
60
50
40
30
20
10
0
950

Coating 141126
HRs,p (0 –10°, 1 030 nm) > 99.95 %GDD-Rp (0 –10°, 1 030 nm) = -250 (±50) fs²

GDD [fs2]

S2: Coating 141181
HR (0°, 1 030 – 1 040 nm) > 99.9 %R (0°, 960 – 982 nm) < 5 %| GDD-R (0°, 1 030 – 1 040 nm) | < 100 fs²
cut on/off R (0°) = T (0°) = 50 % at 994 (±5) nm
AOI 0° → 10° : shift cut/off-wavelength -5 nm
S1: Coating 141184
AR (0°, 950 – 1 050 nm) < 0.2 %wavelength [nm]
990

1000

1010

1020

1030

1040

1050

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B45/ 1 x 0.04
5/ 4 x 0.04

141255141257

1070

1080

Price

390 €
600 €

Standard Items from Stock
ps/fs-Laser [1030–1040 nm]

GTI-Mirror 5°, 1 040 nm, -550 fs2

GTI-Mirror 5°, 1 030 nm, -1 000 fs2

wavelength [nm]
900

950

1000

1050

1100

0

10°

-800

0°

-1000
-1200
-1400
980

R [%]

wavelength [nm]
900

0
-100
-200
-300
-400
-500
-600
-700
-800
-900
-1000
980

wavelength [nm]
990

1000

1010

1020

1030

1040

1050

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B45/ 1 x 0.04
5/ 4 x 0.04

141260141261

1070

1080

Price

408 €
624 €

GTI-Mirror 5°, 1 040 nm, -250 fs2

1050

1100

1150

1200

10°

0°

1000

1050

1000

1010

1020

1030

1040

1050

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B45/ 1 x 0.04
5/ 4 x 0.04

141269141270

1070

1080

Price

390 €
600 €

1100

1150

1200

10°

0°

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

R [%]

R [%]

950

wavelength [nm]990

Coating 141152
HRs,p (0 – 10°, 1 040 nm) > 99.95 %GDD-Rp (0 – 10°, 1 040 nm) = -1 000 (±200) fs²

wavelength [nm]900

wavelength [nm]
900

950

1000

1050

1100

0

-400
-600
-800

1150

10°

-200

GDD [fs2]

0
-50
-100
-150
-200
-250
-300
-350
-400
-450
-500
980

1000

GTI-Mirror 5°, 1 040 nm, -1 000 fs2

Coating 141148
HRs,p (0 – 10°, 1 040 nm) > 99.95 %GDD-Rp (0 –10°, 1 040 nm) = -250 (±50) fs²
100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

950

GDD [fs2]

-600

1200

GDD [fs2]

-200
-400

1150

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

1200

0°

GDD [fs2]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

Coating 141150
HRs,p (0 – 10°, 1 040 nm) > 99.95 %GDD-Rp (0 – 10°, 1 040 nm) = -550 (±100) fs²

R [%]Coating 141151
HRs,p (0 – 10°, 1 030 nm) > 99.95 %GDD-Rp (0 – 10°, 1 030 nm) = -1 000 (±200) fs²-1000

wavelength [nm]
990

1000

1010

1020

1030

1040

1050

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B45/ 1 x 0.04
5/ 4 x 0.04

141263141266

1070

1080

Price

372 €
576 €

-1200
-1400

wavelength [nm]
980

990

1000

1010

1020

1030

1040

1050

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B45/ 1 x 0.04
5/ 4 x 0.04

141273141274

1070

1080

Price

408 €
624 €

115

Standard Items from Stock
ps/fs-Laser [1030–1040 nm]

Separator 22.5°

Thin Film Polarizer 56°, 1 030 nm

S2: Coating 141303
HRs,p (22.5°, 1 030 – 1 050 nm) > 99.8 %Rs,p (22.5°, 900 – 980 nm) < 5 %S1: Coating 141306
ARs,p (22.5°, 900 – 1 000 nm) < 0.2 %S2: Coating 141262
TFP (56° *, 1 030 nm) Rs > 99.9% Rp < 2 %*specifications will be achieved by ±2° angle adjustment
S1: Uncoated; Brewster angle → Rp (56°) ~ 0 %

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1000

s

p

1010

1020

1030

1040

1050

1060

wavelength [nm]
900

950

1000

1050

1100

1150

1200

1250

1300
S2

s

wavelength [nm]
1020

1040

1100

1120

1140

1160

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 3.05 mm
Ø 25.0 mm | t 3.05 mm

A3
B3

5/ 1 x 0.04
5/ 3 x 0.04

142321
142320

1180

1200

Price

258 €
582 €

Thin Film Polarizer 45°, 1 030 nm
S2: Coating 141254
TFP (45° *, 1 030 nm) Rs > 99.9 % Rp < 2 %*specifications will be achieved by ±2° angle adjustment
S1: Coating 141268
ARp (45°, 1 020 – 1 050 nm) < 0.1 %

1010

1020

1030

1040

1050

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141533

1070

1080

Price

345 €

S2: Coating 141264
TFP (56° *, 1 042 nm) Rs > 99.9% Rp < 2 %*specifications will be achieved by ±2° angle adjustment
S1: Uncoated; Brewster angle → Rp (56°) ~ 0 %
100
90
80
70
60
50
40
30
20
10
0

s

p wavelength [nm]
990

1000

1010

1020

1030

1040

1050

1060

1070

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141534

1080

1090

Price

345 €

S2

s

Window 0°

R [%]S2+S1: Coating 141184
AR (0°, 950 – 1 050 nm) < 0.2%

p
1010

1020

1030

wavelength [nm]

1040

1050

Substrate Dimensions

No.

Imperfections

Item #

Ø25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141531

1060

Price

407 €

Thin Film Polarizer 45°, 1 042 nm
S2: Coating 141259
TFP (45° *, 1 042 nm) Rs > 99.9 % Rp < 2 %*specifications will be achieved by ±2° angle adjustment
S1: Coating 141268
ARp (45°, 1 020 – 1 050 nm) < 0.1 %
S2

s

R [%]

116

1000

Thin Film Polarizer 56°, 1 042 nm

1080

100
90
80
70
60
50
40
30
20
10
0
1010

990

p

1060

100
90
80
70
60
50
40
30
20
10
0
1000

p wavelength [nm]R [%]GDD [fs2]

1000
800
600
400
200
0
-200
-400
-600
-800
-1000
1000

850

s

p wavelength [nm]
1020

1030

1040

1050

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141532

1070

Price

407 €

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

S2

S1

T [%]

800

100
90
80
70
60
50
40
30
20
10
0
980

R [%]

S2

R [%]

100
90
80
70
60
50
40
30
20
10
0

wavelength [nm]
800

850

900

950

Substrate DimensionsNo.

Ø 12.7 mm | t 1 mm
Ø 25.0 mm | t 1 mm

A2
B2

1000

1050

1100

1150

Imperfections

Item #Price

5/ 1 x 0.04
5/ 3 x 0.04

141932141935

124 €
230 €

1200

Standard Items from Stockcw/ns-Laser [1030–1064 nm]

cw/ns-Laser [1030–1064 nm]
Pump
Mirror

pump
laser

Pump
MirrorYb:YAG
Nd:YAGsm
ati ionigm sat
ast pencom

Laser
Mirroroc

LBO

optical
diode

EtalonTurning Mirror
22.5-45°

Turning Mirror
22.5-45°

Window

Laser Mirror 0°. . . . . . . . . . . . . . . . . . . . . . . . . . . .  117Pump Mirror 0°. . . . . . . . . . . . . . . . . . . . . . . . . . . .  117Turning Mirror 22.5 – 45°, 1 030 – 1 064 nm . . . . . .  118Turning Mirror 22.5 – 45°, 515 – 532 nm . . . . . . . . .  118Turning Mirror 45°, 1 030 – 1 064 nm . . . . . . . . . . .  118Turning Mirror 45°, 515 – 532 nm . . . . . . . . . . . . . .  118Turning Mirror 45°, 343+515+1 030 nm . . . . . . . . .  118Turning Mirror 45°, 355+532+1 064 nm . . . . . . . . .  119Non-Polarizing Beamsplitter 45°, 1 030 nm . . . . . . .  119Non-Polarizing Beamsplitter 45°, 1 064 nm . . . . . . .  119Non-Polarizing Beamsplitter 45°, 515 nm . . . . . . . .  119Non-Polarizing Beamsplitter 45°, 532 nm . . . . . . . .  120Separator 45°, 515 – 532 / 1 030 – 1 064 nm. . . . . . .  120Separator 45°, 1 030 / 515 nm . . . . . . . . . . . . . . . .  120Separator 45°, 1 064 / 532 nm . . . . . . . . . . . . . . . .  120Separator 45°, p-pol. 343 / 515 / 1 030 nm. . . . . . . .  121Separator 45°, p-pol. 355 / 532 / 1 064 nm. . . . . . . .  121Separator 45°, s-pol. 343 – 355 / 515 – 532 /1 030 – 1 064 nm . . . . . . . . . . . . . . . . . . . . . . . . . . .  121Thin Film Polarizer 56°, 1 030 nm . . . . . . . . . . . . . .  122Thin Film Polarizer 56°, 1 064 nm . . . . . . . . . . . . . .  122Thin Film Polarizer 56°, 515 nm . . . . . . . . . . . . . . .  122Thin Film Polarizer 56°, 532 nm . . . . . . . . . . . . . . .  122Window 0°. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  122

Separator 45°

on request
TFP
56°

NPOL
45°

TFP
56°

NPOL
45°

Turning
Mirror45°

Turning
Mirror45°

For optics not specified here, please visit www.layertec.de, contact us at info@layertec.de or call us at + 49 (0)36453 744 0.

Laser Mirror 0°

Pump Mirror 0°

700

800

900

1000

1100

1200

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

wavelength [nm]600

wavelength [nm]
940

960

980

1000

1020

1040

1060

1080

1100

1120

LIDT
6/ 50 J/cm2; 1064 nm; 7 ns; Ø 270 µm

1140

1160

LAYERTEC

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm

A4
B4
C3

5/ 1 x 0.04
5/ 3 x 0.04
5/ 4 x 0.063

141864141868141866

Price

105 €
143 €
522 €

100
90
80
70
60
50
40
30
20
10
0
100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

S2

R [%]

R [%]

100
90
80
70
60
50
40
30
20
10
0
500

S2: Coating 141325
HRs,p (0 – 10°, 1 030 – 1 064 nm) > 99.95 %Rs,p (0 – 10°, 808 nm) < 2 %S1: Coating 141355
ARs,p (0 – 10°, 808 nm) < 0.2 %wavelength [nm]
700

800

900

1000

1100

1200
S2

R [%]

Coating 141321
HRs,p (0 – 10°, 1 030 – 1 064 nm) > 99.95 %wavelength [nm]
940

960

980

1000

1020

1040

1060

1080

1100

1120

LIDT
6/  30 J/cm2; 1064 nm; 7 ns; Ø 270 µm

1140

1160

LAYERTEC

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4
B45/ 1 x 0.04
5/ 3 x 0.04

141877141881

Price

146 €
222 €

117

Standard Items from Stockcw/ns-Laser [1030–1064 nm]

Turning Mirror 45°, 515 – 532 nm

Coating 141496
Ag + multilayerHRs,p (22.5 – 45°, 1 030 – 1 064 nm) > 99.7 %for application outside the resonatorno transmission @ VIS / NIR

Coating 141329
HRs,p (45°, 515 – 532 nm) > 99.9 %

R [%]

R [%]

1000

1050

1100

1150

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

B4
C3
K2

5/ 3 x 0.04
5/ 4 x 0.063
5/ 3 x 0.04

141942141945141954

1200

Price

138 €
504 €
174 €

99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

R [%]

.5°s
22 °p
.5
22

s
45°

°p
45

500

525

550

575

600

625

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 6.35 mm
25 × 25 mm | t 6.35 mm

B4
K2

5/ 3 x 0.04
5/ 3 x 0.04

141949141956

650

Price

138 €
174 €

Turning Mirror 45°, 1 030 – 1 064 nm
Coating 141327
HRs,p (45°, 1 030 – 1 064 nm) > 99.95 %pswavelength [nm]
900

950

1000

1050

1100

1150

LIDT
6/  50 J/cm2; 1064 nm; 7 ns; Ø 270 µm

118

550

570

590

610

630

650

LAYERTEC

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 6.35 mm
25 × 25 mm | t 6.35 mm

B4
K2

5/ 3 x 0.04
5/ 3 x 0.04

141946141955

Price

138 €
174 €

s

u

300

310

320

p

wavelength [nm]
330

340

350

360

370

380

390

400

100.0
99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

p

u

s

wavelength [nm]
475

485

495

505

515

525

535

545

555

565

575

100.0

1200

LAYERTEC

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5/ 1 x 0.04
5/ 3 x 0.04
5/ 4 x 0.063
5/ 3 x 0.04

141896141500141904141953

Price

105 €
143 €
522 €
183 €

99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

p

u

s

R [%]

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

530

100.0

wavelength [nm]
475

510

Coating 128809
HRu (45°, 343 nm) > 99.4 %HRu (45°, 515 nm) > 99.8 %HRu (45°, 1 030 nm) > 99.9 %Coating 141497
Ag + multilayerHRs,p (22.5 – 45°, 515 – 532 nm) > 99.7 %for application outside the resonatorno transmission @ VIS / NIR

450

490

Turning Mirror 45°, 343+515+1 030 nm

Turning Mirror 22.5 – 45°, 515 – 532 nm

100.0
99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

wavelength [nm]
470

R [%]

950

s

LIDT
6/  10 J/cm2; 532 nm; 7 ns; 10Hz; Ø 270 µm

wavelength [nm]
900

p

R [%]

22.5
°p

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
450

°s
45

45

°p

100.0
99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

22.5°
s

Turning Mirror 22.5 – 45°, 1 030 – 1 064 nm

wavelength [nm]
950

970

990

1010

1030

1050

1070

1090

1110

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 6.35 mm

B4

5/ 2 x 0.04

128931

1130

1150

Price

467 €

Standard Items from Stockcw/ns-Laser [1030–1064 nm]

Turning Mirror 45°, 355+532+1 064 nm

Non-Polarizing Beamsplitter 45°, 1 064 nm
S2: Coating 141338
PRs,p (45°, 1 064 nm) = 50 (±3) %| Rs – Rp | < 4 %S1: Coating 141331
ARs,p (45°, 1 030 – 1 064 nm) < 0.7 %| Rs – Rp | < 0.2 %Coating 115420
HRu (45°, 355 nm) > 99.4 %HRu (45°, 532 nm) > 99.8 %HRu (45°, 1 064 nm) > 99.8 %

u

p

310

320

330

340

350

360

370

380

390

400

R [%]

p u

s

wavelength [nm]
475

485

495

505

515

525

535

545

555

565

575

100.0

s

R [%]

99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

p

p

wavelength [nm]
1020

1030

1040

1050

1060

1070

1080

1090

1100

1110
S1

s
p

wavelength [nm]
900

950

1000

1050

1100

1150

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141607

1200

Price

270 €

Non-Polarizing Beamsplitter 45°, 515 nm
wavelength [nm]
950

970

990

1010

1030

1050

1070

1090

1110

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 6.35 mm

B4

5/ 2 x 0.04

110837

1130

1150

Price

467 €

S2

R [%]

s
p

wavelength [nm]
980

990

1000

1010

1020

1030

1040

S2: Coating 141344
PRs,p (45°, 515 nm) = 50 (±3) %| Rs – Rp | < 4 %S1: Coating 141341
ARs,p (45°, 515 – 532 nm) < 0.7 %| Rs – Rp | < 0.2 %
100
90
80
70
60
50
40
30
20
10
0
500

S2

s
p

R [%]

S2: Coating 141335
PRs,p (45°, 1 030 nm) = 50 (± 3) %| Rs – Rp | < 4 %S1: Coating 141331
ARs,p (45°, 1 030 – 1 064 nm) < 0.7 %| Rs – Rp | < 0.2 %

1050

1060

1070

1080
S1

s

R [%]

2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0

2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0

u

Non-Polarizing Beamsplitter 45°, 1 030 nm

100
90
80
70
60
50
40
30
20
10
0

s

R [%]

wavelength [nm]
300

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

S2

R [%]

s

100
90
80
70
60
50
40
30
20
10
0
1010

p

2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0

wavelength [nm]
505

510

515

520

525

530

535

540

545

550
S1

R [%]

99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

R [%]

100.0

s
p
wavelength [nm]

480

490

500

510

520

530

540

550

560

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141608

570

580

Price

270 €

wavelength [nm]
900

950

1000

1050

1100

1150

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141604

1200

Price

270 €

119

Standard Items from Stockcw/ns-Laser [1030–1064 nm]

Non-Polarizing Beamsplitter 45°, 532 nm

Separator 45°, 1 030 / 515 nm

S2: Coating 141346
PRs,p (45°, 532 nm) = 50 (±3) %| Rs – Rp | < 4 %S1: Coating 141341
ARs,p (45°, 515 – 532 nm) < 0.7 %| Rs – Rp | < 0.2 %S2: Coating 159375
HRs,p (45°, 1 030 nm) > 99.9 %Rs,p (45°, 515 nm) < 3 %S1: Coating 141341
ARs,p (45°, 515  nm) < 0.7%
| Rs - Rp | < 0.2%

p

520

525

530

535

540

545

550

555

560
S1

R [%]

2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0

wavelength [nm]515sp
wavelength [nm]

480

490

500

510

520

530

540

550

560

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141609

570

580

10
9
8
7
6
5
4
3
2
1
0

S2

s
p

wavelength [nm]
950

970

990

1010

1030

1050

485

495

505

515

525

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 6.35 mm

B4

5/ 2 x 0.04

160937

Separator 45°, 1 064 / 532 nm
S2: Coating 159374
HRs,p (45°, 1 064 nm) > 99.9 %Rs,p (45°, 532 nm) < 3 %S1: Coating 141341
ARs,p (45°, 532 nm) < 0.7%
| Rs - Rp| < 0.2%

wavelength [nm]450 460 470 480 490 500

S2

R [%]

10
9
8
7
6
5
4
3
2
1
0
1000

510 520 530 540 550 560 570 580 590 600sp
wavelength [nm]
1010

1020

1030

1040

1050

1060

1070

1080

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm
Ø 25.0 mm | t 6.35 mm

B3
B4

5/ 3 x 0.04
5/ 3 x 0.04

141892141895

1090

1100

Price

216 €
200 €

1150

535

545

555

565

Price

390 €

100.0

10
9
8
7
6
5
4
3
2
1
0

S2

s

p

R [%]

99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

575

wavelength [nm]
950

980

1010

1040

1070

1100

1130

1160

1190

1220

1250
S2

R [%]

R [%]

s

1130

wavelength [nm]475

S2: Coating 141359
HRs,p (45°, 515 – 532 nm) > 99.8 %Rs (45°, 1 030 – 1 064 nm) < 5 %Rp (45°, 1 030 – 1064 nm) < 2 %S1: Coating 141377
ARs,p (45°, 1 030 – 1 064 nm) < 0.7 %
p

1110

p

270 €

S2

1090

s

Separator 45°, 515 – 532 / 1 030 – 1 064 nm

99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

1070

S2

Price

100.0

120

99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0

R [%]

s

100.0

R [%]

S2

R [%]

100
90
80
70
60
50
40
30
20
10
0
510

s

p

wavelength [nm]
475

485

495

505

515

525

535

545

555

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 6.35 mm

B4

5/ 2 x 0.04

160936

565

575

Price

390 €

Standard Items from Stockcw/ns-Laser [1030–1064 nm]

10
9
8
7
6
5
4
3
2
1
0
1000

Separator 45°, p-pol. 343 / 515 / 1 030 nm

R [%]S2: Coating 122334
HRp (45°, 343 nm) > 99.0 %Rs (45°, 515 nm) < 3 %Rp (45°, 1 030 nm) < 2%
S1: Coating 122335
ARs (45°, 515 nm) < 0.5%
ARp (45°, 1 030 nm) < 0.5%
100.0

p
R [%]

s

310

320

330

340

350

360

370

380

390

400
S2

s

1030

1040

1050

1060

1070

1080

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 2 x 0.04

109816

1090

1100

370 €

S2: Coating 115258
HRs (45°, 343 – 358 nm) > 99.9 %Rp (45°, 515 – 532 nm) < 1 %Rs (45°, 1 030 – 1 064 nm) < 1%
S1: Coating 116338
ARp (45°, 515 – 535 nm) < 0.3%
ARs (45°, 1 030 – 1 064 nm) < 0.2%

wavelength [nm]
485

495

505

515

525

535

545

555

565

575
S2

R [%]

s

p
wavelength [nm]
1010

1020

1030

1040

1050

1060

1070

1080

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 2 x 0.04

160935

1090

1100

Price

370 €

99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0

S2

p

wavelength [nm]
300

310

320

330

340

350

360

370

380

390

s

p
wavelength [nm]
475

485

495

505

515

525

535

545

555

565

575
S2

R [%]

100.0

400
S2

5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1000

S2: Coating 115203
HRp (45°, 355 nm) > 99.5 %Rs (45°, 532 nm) < 5 %Rp (45°, 1 064 nm) < 5%
S1: Coating 128506
ARs (45°, 535 nm) < 0.5%
ARp (45°, 1 064 nm) < 0.5%

s

R [%]

p

475

Price

100.0

Separator 45°, p-pol. 355 / 532 / 1 064 nmspwavelength [nm]
1010

1020

1030

1040

1050

1060

1070

1080

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 6.35 mm

B4

5/ 2 x 0.04

116540

1090

1100

S2

p

442 €

R [%]

s

Price

wavelength [nm]
300

310

320

330

340

350

360

370

380

390

400
S2

R [%]

10
9
8
7
6
5
4
3
2
1
0

1020

Separator 45°, s-pol. 343 – 355 / 515 – 532 / 1 030 – 1 064 nm
wavelength [nm]

300

10
9
8
7
6
5
4
3
2
1
0
1000

99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

wavelength [nm]
1010

R [%]

10
9
8
7
6
5
4
3
2
1
0

s

p

S2

R [%]

99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

S2

s

p

wavelength [nm]
475

485

495

505

515

525

535

545

555

565

575

121

Standard Items from Stockcw/ns-Laser [1030–1064 nm]

Thin Film Polarizer 56°, 1 030 nm

Thin Film Polarizer 56°, 532 nm

S2: Coating 141352
TFP (56° *, 1 030 nm) Rs > 99.9 % Rp < 2 %*specifications will be achieved by ± 2° angle adjustment
S1: Uncoated; Brewster angle → Rp (56°) ~ 0 %S2: Coating 141351
TFP (56° *, 532 nm) Rs > 99.9 % Rp < 2 %*specifications will be achieved by ± 2° angle adjustment
S1: Uncoated; Brewster angle → Rp (56°) ~ 0 %

100
90
80
70
60
50
40
30
20
10
0

100
90
80
70
60
50
40
30
20
10
0
510

p
980

990

1000

1040

1050

R [%]

R [%]

s

wavelength [nm]

1010

1020

1030

1060

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141535

1070

1080

Price

345 €

p
515

520

540

530

535

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141539Window 0°

S2: Coating 141353
TFP (56° *, 1 064 nm) Rs > 99.9 % Rp < 2 %*specifications will be achieved by ± 2° angle adjustment
S1: Uncoated; Brewster angle → Rp (56°) ~ 0 %S2+S1: Coating 141348
AR (0°, 515 – 532 nm) < 0.5 %AR (0°, 1 030 – 1 064 nm) < 0.3 %p wavelength [nm]
1030

1040

1050

1060

1070

1080

1090

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141536

1100

1110

Price

345 €

Thin Film Polarizer 56°, 515 nm
S2: Coating 141350
TFP (56° *, 515 nm) Rs > 99.9 % Rp < 2 %*specifications will be achieved by ± 2° angle adjustment
S1: Uncoated; Brewster angle → Rp (56°) ~ 0 %

s

R [%]

100
90
80
70
60
50
40
30
20
10
0
490

p
495

500

520

555

560

Price

345 €

S2

S1

wavelength [nm]
460

100.0
99.5
99.0
98.5
98.0
97.5
97.0
96.5
96.0
95.5
95.0
980

480

500

520

540

560

580
S2

S1

T [%]

1020

550

T [%]

R [%]

s

100.0
99.8
99.6
99.4
99.2
99.0
98.8
98.6
98.4
98.2
98.0

545

wavelength [nm]525Thin Film Polarizer 56°, 1 064 nm

100
90
80
70
60
50
40
30
20
10
0
1010

122

s

525

wavelength [nm]

505

510

515

530

Substrate Dimensions

No.

Imperfections

Item #

Ø 25.0 mm | t 3.05 mm

B3

5/ 3 x 0.04

141537

535

540

Price

345 €

wavelength [nm]
1010

1040

1070

1100

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 1 mm
Ø 25.0 mm | t 3.05 mm

A2
B3

5/ 1 x 0.04
5/ 3 x 0.04

141890141885

1130

Price

126 €
156 €

Standard Items from Stock
2 μm [Ho:YAG | Tm:YAG]

2 mü
2 μm [Ho:YAG | Tm:YAG]
Pump
Mirrorpump
laser

Short Wave
Pass Filter
45°

Turning
Mirror
45°

crystalTurning Mirror 45° . . . . . . . . . . . . . . . . .  123Output Coupler 70 % . . . . . . . . . . . . . . .  123Output Coupler 80 % . . . . . . . . . . . . . . .  123Output Coupler 95 % . . . . . . . . . . . . . . .  124GTI-Mirror 5°, -500 fs2 . . . . . . . . . . . . . .  124Short Wave Pass Filter 45° . . . . . . . . . . .  124Thin Film Polarizer 55° . . . . . . . . . . . . . .  124

Short Wave
Pass Filter
45°
TFP 55°

OutputCoupler

GTIMirror 5°

Output Coupler 80 %Turning Mirror 45°
Coating 160406 on Fused Silica IR grade
HRs (45°, 2 090 nm) > 99.9 %
s

90
80
70
60
50
40
30
20
10
0
1800

R [%]

wavelength [nm]
1900

2000

2100

2200

2300

Substrate Dimensions

No.

Imperfections Item #Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4 b
B4 b

5/ 2 x 0.025
5/ 2 x 0.04

103180160659

2400

Price

168 €
360 €

1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1800

wavelength [nm]
1900

2000

2100

2200

2300
S1

R [%]

Output Coupler 70 %S2: Coating 113886 on Fused Silica IR grade
PR (0°, 2 010  –  2 100 nm) = 70 (±2) %S1: Coating 116213
AR (0°, 2 010  –  2 100 nm) < 0.25 %S2

100

wavelength [nm]
1900

2000

2100

2200

Substrate Dimensions

No.

Imperfections Item #Ø 12.7 mm | t 6.35 mm

A4 b

5/ 2 x 0.025

100415

2300

Price

147 €

R [%]

90
80
70
60
50
40
30
20
10
0
1800

S2

100

p

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1800

S2: Coating 160390 on Fused Silica IR grade
PR (0°, 2 010  –  2 100 nm) = 80 (±2) %S1: Coating 116213
AR (0°, 2 010  –  2 100 nm) < 0.25 %

2000

2100

2200

2300
S1

R [%]

1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1800

wavelength [nm]1900

wavelength [nm]
1900

2000

2100

2200

Substrate Dimensions

No.

Imperfections Item #Ø 12.7 mm | t 6.35 mm

A4 b

5/ 2 x 0.025

102671

2300

Price

147 €

123

Standard Items from Stock
2 μm [Ho:YAG | Tm:YAG]

Output Coupler 95 %Short Wave Pass Filter 45°

S2: Coating 160391 on Fused Silica IR grade
PR (0°, 2 010  –  2 100 nm) = 95 (±1) %S1: Coating 116213
AR (0°, 2 010  –  2 100 nm) < 0.25 %S2: Coating 115311 on Fused Silica IR gradeHRs,p (45°*, 2 090 nm) > 99.8 %Rs,p (45°*, 1 908 nm) < 3 %*specifications will be achieved by ± 3° angle adjustment
S1: Coating 123893
ARs,p (45°, 1 908 nm) < 0.6 %

S2

100
99
98
97
96
95
94
93
92
91
90
1800

90
80
70
60
50
40
30
20
10
0
1600

2000

2100

2200

2300
S1

2000

2100

2200

No.

Imperfections Item #Ø 12.7 mm | t 6.35 mm

A4 b

5/ 2 x 0.025

107781

2300

Price

147 €

GTI-Mirror 5°, -500 fs2

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1900

wavelength [nm]
1700

1800

1900

2000

2100

2200

2300

2400

2500

2600
S2

p

s

20
18
16
14
12
10
8
6
4
2
0
1900

R [%]

wavelength [nm]
1850

1900

1950

2000

2050

2100

2150

2200

wavelength [nm]
1920

1940

1960

1980

2000

2020

2040

2060

2080

2100

2120

2140
S2

s

p

R [%]

Coating 159365
HR (0 – 5°, 2 010  –  2 100 nm) > 99.9 %GDD-R (0 – 5°, 2 010  –  2 100 nm) = -500 (±150) fs²
without GDD measurement

2250

wavelength [nm]
1920

1940

1960

1980

2000

2020

2040

2060

2080

2100

Substrate Dimensions

No.

Imperfections Item #Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm

A4 b
B4 b

5/ 2 x 0.025
5/ 3 x 0.04

2120

2140

Price

110072112699

420 €
870 €

Thin Film Polarizer 55°
Coating 113900 on Fused Silica IR grade
TFP (55°*, 2 090 nm) Rs > 99.9 % Rp < 1 %*specifications will be achieved by ± 3° angle adjustment

2300

0
-100
100

90
80
70
60
50
40
30
20
10
0
2000

R [%]

GDD [fs2]

124

p

R [%]

R [%]

wavelength [nm]1900

Substrate Dimensions

-200
-300
-400
-500
-600
-700
-800
-900
-1000
1900

s

R [%]

R [%]

wavelength [nm]
1900

1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1800

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
1800

S2

100

wavelength [nm]
1950

2000

2050

2100

2150

Substrate Dimensions

No.

Imperfections Item #Ø 25.0 mm | t 6.35 mm

B4

5/ 2 x 0.04

160660

2200

Price

720 €

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
2050

p

s
s

2070

2090

2110

2130

2150

wavelength [nm]
2020

2040

2060

2080

2100

2120

2140

2160

Substrate Dimensions

No.

Imperfections Item #Ø 25.0 mm | t 3.0 mm

B3 b

5/ 2 x 0.04

102787

2180

2200

Price

557 €

Standard Items from Stock
3 μm [Er:YAG]

3 mü
3 μm [Er:YAG]
Laser
MirrorOutputCoupler

Turning
Mirror 45°+ Red

Turning
Mirror 45°+ Red

Er:YAG

Turning
Mirror 45°+ Red

Turning
Mirror 45°
withoutRed

pilot laser

Laser Mirror 0°, high power . . . . . . . . . .  125Output Coupler 80 % . . . . . . . . . . . . . . .  125Output Coupler 85 % . . . . . . . . . . . . . . .  125Output Coupler 90 % . . . . . . . . . . . . . . .  126Turning Mirror 45°, Red R > 95% . . . . . .  126Turning Mirror 45°, Red R < 20% . . . . . .  126

For optics not specified here, please visit www.layertec.de, contact us at info@layertec.de or call us at + 49 (0)36453 744 0.

Output Coupler 85 %Laser Mirror 0°, high power
Coating 160428 on Sapphire
HR (0°, 2 940 nm) > 99.8 %

2800

2850

2900

2950

3000

3050

3100

Substrate Dimensions

No.

Imperfections Item #Ø 12.7 mm | t 3.0 mm
Ø 25.4 mm | t 3.0 mm

A3 e
B3 e

5/ 2 x 0.04
5/ 2 x 0.063

100417100418

3150

3200

Price

177 €
320 €

1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
2800

wavelength [nm]
2750

2800

2850

2900

2950

3000

3050

3100

3150

3200
S1

R [%]

S2: Coating 160426 on Sapphire
PR (0°, 2 940 nm) = 80 (±2) %S1: Coating 120759
AR (0°, 2 940 nm) < 0.25 %
S2

100
95

wavelength [nm]
2850

2900

2950

3000

3050

Substrate Dimensions

No.

Imperfections Item #Ø 12.7 mm | t 3.0 mm

A3 e

5/ 2 x 0.04

109581

3100

Price

177 €

R [%]

90
80

97
94
91
88
85
82
79
76
73
70
2700

R [%]

wavelength [nm]2750

Output Coupler 80 %

85

S2

100

R [%]

100.0
99.9
99.8
99.7
99.6
99.5
99.4
99.3
99.2
99.1
99.0
2700

S2: Coating 160425 on Sapphire
PR (0°, 2 940 nm) = 85 (±2) %S1: Coating 120759
AR (0°, 2 940 nm) < 0.25 %

75
70
65
60
2700

2800

2850

2900

2950

3000

3050

3100

3150

3200
S1

R [%]

1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
2800

wavelength [nm]2750

wavelength [nm]
2850

2900

2950

3000

3050

Substrate Dimensions

No.

Imperfections Item #Ø 12.7 mm | t 3.0 mm

A3 e

5/ 2 x 0.04

109753

3100

Price

177 €

125

Standard Items from Stock
3 μm [Er:YAG]

Output Coupler 90 %Turning Mirror 45°, Red R < 20%

S2: Coating 135719 on Sapphire
PR (0°, 2 940 nm) = 90 (±1) %S1: Coating 120759
AR (0°, 2 940 nm) < 0.25 %Coating 115132 on Sapphire
HRu (45°, 2 940 nm) > 99 %Ru (45°, 635 – 655 nm) < 20 %S2wavelength [nm]
2750

2800

2850

2900

2950

3000

3050

3100

3150

3200
S1

R [%]

1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
2800

wavelength [nm]
2850

2900

2950

3000

3050

Substrate Dimensions

No.

Imperfections Item #Ø 12.7 mm | t 3.0 mm

A3 e

5/ 2 x 0.04

3100

Price

100419177 €Turning Mirror 45°, Red R > 95%
Coating 113862
HRu (45°, 2 940 nm) > 99.5 %spRu (45°,635 – 655 nm)> 95 %

u

100
99

s

wavelength [nm]
2600

2700

2800

2900

3000

100
99

126

3100

3200

3300

3400

s
u
p

R [%]

98
97
96
95
94
93
92
91
90

u

p

R [%]

98
97
96
95
94
93
92
91
90
2500

wavelength [nm]
600

98
97
96
95
94
93
92
91
90
2600

610

620

630

640

650

660

Substrate Dimensions

No.

Imperfections Item #Ø 25.4 mm | t 3.05 mm

B3

5/ 2 x 0.063

160977

670

680

Price

287 €

10
9
8
7
6
5
4
3
2
1
0

wavelength [nm]
2700

R [%]

R [%]

98
96
94
92
90
88
86
84
82
80
2700

100
99

R [%]

100

2800

2900

3000

3100

3200

3300

s
u
p

600

wavelength [nm]
610

620

630

640

650

660

Substrate Dimensions

No.

Imperfections Item #Ø 25.4 mm | t 3.0 mm

B3 e

5/ 2 x 0.063

109093

670

680

Price

320 €

Standard Items from Stock
Metallic Mirrors

Metallic Mirrors
Unprotected Gold Mirror . . . . . . . . . . . . . . . . . . . .  127Protected Gold Mirror . . . . . . . . . . . . . . . . . . . . . .  127Protected Silver Mirror, 600 – 1 000 nm . . . . . . . . . .  127Protected Silver Mirror, 800 – 2 000 nm . . . . . . . . . .  128Protected Aluminum Mirror, UV-range . . . . . . . . . .  128Protected Aluminum Mirror, UV-VIS-range . . . . . . .  128

Unprotected Gold Mirror

Protected Silver Mirror, 600 – 1 000 nm

s
45°
10°
°p
45

100
99

800

1000

1200

1400

1600

LIDT
6/ 0.5 J/cm2; 795 nm; 42 fs; 1 kHz; Ø 80 µm

1800

2000

2200

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5 / 2 x 0.025
5 / 2 x 0.04
5 / 6 x 0.04
5 / 2 x 0.04

142064142065142066142067

Price

78 €
114 €
414 €
138 €

-2
-4
-6
-8
-10
500

Protected Gold Mirror

100
99

°p

45

wavelength [nm]
800

1000

1200

1400

800

900

1600

LIDT
6/ 0.2 J/cm2; 795 nm; 42 fs; 1 kHz; Ø 80 µm

1800

2000

1000

1100

45°p
0°
45°s
wavelength [nm]
600

700

800

1000

900

1100

LAYERTEC
WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5 / 2 x 0.025
5 / 2 x 0.04
5 / 6 x 0.04
5 / 2 x 0.04

142089142088142086142083

Price

75 €
100 €
336 €
130 €

Measurement

R [%]

°s
45
10°

600

700

LIDT
6/ 5 J/cm2; 1 064 nm; 7 ns; 10 Hz; Ø 480 µm
6/ 0.7 J/cm2; 795 nm; 42 fs; 1 kHz; Ø 80 µm

Coating 140777
Au + protection layer
HR (0°, 800 – 4 000 nm) > 95 %HRs (45°,
800 – 4gold
000 nm)> 95 %
140777protected
mirrorHRp (45°, 800 – 4 000 nm) > 94 %

98
97
96
95
94
93
92
91
90

140780 protected silver mirror, 600-1000nm wavelength
GDD [nm]
10
8
6
4
2
0

WRCP Budapest

s

98
45°
10°
97
96
45°p
95
94
93
92
91
90
500
600
R [%]

wavelength [nm]600

Measurement

R [%]

98
97
96
95
94
93
92
91
90

GDD-R [fs2]10099Coating 140780
Ag + protection layer, fs-opt. 600 – 1 000 nm
HR (0°, 600 – 1 000 nm) > 97 %HRs (45°, 600 – 1 000 nm) > 96 %HRpprotected(45°, 600 –silver
1 000 nm)
> 96600-1000nm%
140780
mirror,| GDD-Rs,p (0 – 45°, 600 – 1 000 nm) | < 10 fs²

Measurement

Coating 140770
Au unprotected
HR (0°, 800 – 20 000 nm) > 98 %HRs (45°, 800 – 20 000 nm) > 98 %140770 unprotected gold mirror
HRp (45°, 800 – 20 000 nm) > 97 %2200

WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5 / 2 x 0.025
5 / 2 x 0.04
5 / 6 x 0.04
5 / 2 x 0.04

142074142075142076142077

Price

84 €
118 €
432 €
148 €

127

Standard Items from Stock
Metallic Mirrors

Protected Silver Mirror, 800 – 2 000 nm

Protected Aluminum Mirror, UV-range

Coating 140831
Ag + protection layer, fs-opt. 800 – 2 000 nm
HR (0°, 800 – 2 000 nm) > 97 %HRs (45°, 800 – 2 000 nm) > 98 %HRpprotected(45°, 800 –silver
2 000 nm)> 97800-2000nm%
140831mirror,| GDD-Rs,p (0 – 45°, 800 – 2 000 nm) | < 5 fs²

Coating 142407
Al enhanced, 260 – 360 nm opt.
HRs,p (0silver– 45°, 260– 360UV-rangenm) ≥ 90 %x protected
mirror,| GDD-Rs,p (0 – 45°, 260 – 360 nm) | < 1 fs2
100

600

800

GDD-R [fs2]

0°
45°p

1000

1200

1400

1600

1800

2000

Measurement

2200

x protected silver mirror, UV-Range GDD
1.0
0.8
0.6
0.4
0.2
0.0

800

260

1000

1200

1400

1600

LIDT
6/ 5 J/cm2; 1 064 nm; 7 ns; 10 Hz; Ø 480 µm
6/ 0.7 J/cm2; 795 nm; 42 fs; 1 kHz; Ø 80 µm

1800

2000

2200

LAYERTEC
WRCP Budapest

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5 / 2 x 0.025
5 / 2 x 0.04
5 / 6 x 0.04
5 / 2 x 0.04

142093142094142096142099

Price

83 €
108 €
357 €
143 €

280

300

320

wavelength [nm]

340

360

380

400

0°

-0.2
-0.4
-0.6
-0.8
-1.0
240

45°s

wavelength [nm]
600

45°p

GDD-R [fs2]°p45140831 protected silver mirror, 800-2000nm,wavelength
GDD [nm]
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
-0.4
-0.6
-0.8
-1.0

45°s
10°

R [%]

s

45°
10°

R [%]

98
97
96
95
94
93
92
91
90

98
96
94
92
90
88
86
84
82
80
240

Measurement

100
99

45°p
45°s

wavelength [nm]
260

280

300

320

340

360

380

Substrate Dimensions

No.

Imperfections

Item #

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

A4
B4
C3
K2

5 / 2 x 0.025
5 / 2 x 0.04
5 / 6 x 0.04
5 / 2 x 0.04

142415142416142417142418

400

Price

88 €
126 €
465 €
170 €

Protected Aluminum Mirror, UV-VIS-range
Coating 140842
Al + protection layerHRs,p (0 – 45°, 266 + 400 + 800 nm) > 80 %| GDD-Rs,p(0 – 45°,266+ 400 +266+400+800
800 nm) | < 10 fs²nm
140842protected
silvermirror,for polarization-sensitive and low-power ultrafast applications
100

45°s
10°

[nm]
140842 protected silver mirror, 266+400+800wavelength
nm, GDD

-2
-4
-6
-8
-10

128

280

360

440

520

600

680

760

840

GDD-R [fs2]

10
8
6
4
2
0

920

0°

Measurement

45°p

R [%]

95
90
85
80
75
70
65
60
55
50
200

1000

45°p

45°s
wavelength [nm]
200

300

400

500

Substrate Dimensions

Ø 12.7 mm | t 6.35 mm
Ø 25.0 mm | t 6.35 mm
Ø 50.0 mm | t 9.5 mm
25 × 25 mm | t 6.35 mm

600

700

800

No.

Imperfections

Item #

A4
B4
C3
K2

5 / 2 x 0.025
5 / 2 x 0.04
5 / 6 x 0.04
5 / 2 x 0.04

142069142071
142091
142092

1000

900

Price

54 €
90 €
330 €
120 €

Standard Items from Stock
Low Loss Mirrors for CRD-Measurements

Low Loss Mirrors for CRD-Measurements
vacuum chamber

scientific toy

photodetector

Attenuation[dB]

Intensity I

-60
- 50
- 40
-30
-20
-10
-6
-3
-1
0

I0

I 0 1eTime t0

Percent[%]
0.000 1
0.001
0.01
0.1
1
10
25.1
50.1
79.4
100

Parts per million
[ppm]

1
10
100
1 000
10 000100 000
251 200
501 200
794 300
1 000 00
0

For optics not specified here, please visit www.layertec.de, contact us at info@layertec.de or call us at + 49 (0)36453 744 0.

Principal Curves of Reflectance and TransmittanceTransmission

Reflectivity

λmax = cwl + Δλ /2cwl

λmin = cwl – Δλ /2

Δλ

RCWL
[%]

T (λmin, λmax)

TCWL

wavelength

Figure1: Principal curve of reflectivity of a low loss mirror anddefinition of central wavelength (CWL) and bandwidth (Δλ)
TCWL
[ppm]

Δλ

R
[%]

T
[ppm]

350 	 (±7) nm > 99.95

30

35 nm

99.93

50

520 	(±10) nm > 99.99

20

60 nm

99.98 100640 	(±15) nm > 99.99

20

80 nm

99.98 100

760 	(±15) nm > 99.995

15

110 nm

99.99 100

960 	(±20) nm > 99.995

20

110 nm

99.99 100

1 045 	(±20) nm > 99.995

20

120 nm

99.99 100

1 260 	(±20) nm > 99.995

15

190 nm

99.99 100

1 392 	(±20) nm > 99.995

15200 nm

99.99 100

1 550 	(±20) nm > 99.99

50

130 nm

99.99 100

1 670 	(±20) nm > 99.99

25

180 nm

99.99 100

1 980 	(±20) nm > 99.99

25

180 nm

99.99 100

2 300 	(±30) nm > 99.99

25

220 nm

99.99 100

CWL

cwl

λmin = cwl – Δλ /2

R (λmin, λmax)

λmax = cwl + Δλ /2

RCWL

Δλ

wavelength

Figure 2: Principal curve of transmission of a low loss mirror anddefinition of central wavelength (CWL) and bandwidth (Δλ)

Substrate Dimensions
[mm]

No.

Imperfections

Item #PriceØ 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000
Ø 12.7 I t 6.35 I CC 1000
Ø 25.0 I t 6.35 I CC 1000

R13
S13
R13
S13
R13
S13
R13
S13
R13
S13
R13
S13
R13
S13
R13
S13
R13
S13
R13
S13
R13
S13
R13
S13

Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016
Øe 8 5/ 2 x 0.016
Øe 20 5/ 2 x 0.04 I Øe10 5/ 2 x 0.016

140970140949140969140964140968140965140967140966140992140974140973140971140991140975140989140976140987140977140986140980140984140981
140983140982

234 €
474 €
234 €
474 €
234 €
474 €
234 €
474 €
234 €
474 €
234 €
474 €
234 €
474 €
234 €
474 €
234 €
474 €
234 €
474 €
234 €
474 €
234 €
474 €

Low Loss Mirrors are shipped with individual CRD measurement reports (reflectance and transmittance). CRD measurement
reports can also be requested individually for all Low Loss Mirrors in stock.
129

Standard Items from Stock
Low Loss Mirror Set for High Finesse Cavities

Low Loss Mirror Set for High Finesse Cavities
Please contact us regarding your coating specifications.

Low Loss Mirror
plane / plane

Low Loss Mirror
CC / planeSpacerMaterial sample

frequency

Compensation
Ring

Compensation
Ring

BundleCC 1 000 / Plane Substrate

Customized Coating on ULE or Fused Silica
batch
up to
8 substrates (free choice)Dimensions:1Øcoating
25.0 mm,
t 6.35mm(No. B4 g/h) Typical yield and cleanliness: see tables page 35
S2: plane, λ /10,
HR-coating ØCustomized
7 mm (withcoatings
Øe 5 mm)for HR- and AR sideedge area: polished for optical contacting to spacers
S1: plane, λ /10,
AR-coating Ø 5 mm (with Øe 4 mm)
Low Loss
MirrorLaser
engravingxedgex xarea:
polished
for optical contacting
plane / planeSpacerto compensation ring

Customized Coating on ULE or Fused Silica
Spectral
CRDt measurement
reflectance&T
Dimensions:Ø25.0 mm,
6.35 mm, CC 1of000mm(No. T1 a/b) transmittance in vacuum with ppm accuracy
S2: CC 1 000 mm, λ /10,
HR-coating Ø 9
mm (with Øe report
6 mm) and clean-room
Measurement
edge area: polished
for opticalto spacers
packaging(singlecontacting
item packaging)S1: plane, λ /10,
AR-coating Ø 5 mm (with Øe 4 mm)
LowBundle
Loss Mirror
price
edge
area: polishedoptical
5 000 –for
7 000
€ contacting
CC / plane
to compensation ringR

λ / 10xxx

Øe 4 mm
R 1000 HR

ULE orFused Silica

Principal sketchCC/plλ / 10λ / 10pl/pl

ARfrequency

Compensation
Ring

Compensation
Ring
ULE orFused Silica

S1

5 mm

9 mm

19 mm

Øe 4 mm
AR

25 mm

HR

S2

Øe 6 mm

S1

5 mm

S2

Material sample

7 mm

25 mm

Øe 5 mm

λ / 10

Plane / Plane Substrate

Principal sketch

Bundle1 coating batch up to 8 substrates (free choice)Typical yield and cleanliness: see tables page 35
Customized coatings for HR- and AR sidexxx

Laser engraving

R

T

xxx

Bundle priceSpectral CRD measurement of reflectance &transmittance in vacuum with ppm accuracy
Measurement report and clean-room
packaging (single item packaging)
5 000 – 7 000 €Please contact us regarding your coating specifications (wavelength, finesse range, required transmittance). Depending on
wavelengths and coating complexity, the achievable reflectance may differ. Therefore, it is validated before shipping by in-house CRD
measurements.

130

Standard Items from Stock
Low Loss Mirror Set for High Finesse Cavities

Example Coating 1
Low Loss Mirror for 1 Wavelength
HR (0°, 1 542 nm) > 99.998 %LL for
1 Wavelength.
T (0°,
1 542 nm) ~ 5 –R7(0°.
ppm1550 nm)

LL for 1 Wavelength. T (0°. 1550 nm)

1490

1510

1530

1550

Substrate DimensionsNo.

Ø 25.0 | t 6.35
Ø 25.0 | t 6.35 | CC 1000

B4 g / h
T1 a / b

1570

1590

1610

Batch

1630

1650

20
18
16
14
12
10
8
6
4
2
0
1450

Price

1*

S2

5 800 €

*1 batch up to 8 pieces

wavelength [nm]
1470

1490

1510

1530

1550

1570

PiecesImperfections

42
2

5 / 1 x 0.006
5 / 1 x 0.01
5 / 1 x 0.025

1590

1610

1630

Measurement in vacuum

R [%]wavelength [nm]1470

Measurement in vacuumS2

99.99999.99899.99799.99699.99599.99499.99399.99299.99199.9901450

T [ppm]100.000

1650

Defect distribution within 1 batch (up to 8 pieces)

Example Coating 2
Low Loss Mirror for 3 Wavelengths
HR (0°, 647 nm) > 99.996 % | HR (0°, 871+920 nm) > 99.99 %647 nm) ~ 5 – 10
ppm | T (0°, 871 nm) ~ 5 – 15 ppm | T (0°, 920 nm) ~ 20 – 30 ppm
LL forT3(0°,Wavelengths.
R (Overview)
100

800

850

900

950

1000

100.000

1050

R [%]

LL for 3 Wavelengths. R (880nm)
640

650

660

wavelength [nm]
670

680

690

700

wavelength [nm]
840

850

860

870

880

Substrate DimensionsNo.

Ø 25.0 | t 6.35
Ø 25.0 | t 6.35 | CC 1000

B4 g / h
T1 a / b*1 batch up to 8 pieces

890

900

Batch

1*

910

920

Price

6 500 €

Measurement in vacuum

S2

R [%]

100.000
99.99999.99899.99799.99699.99599.99499.99399.99299.99199.990830

630

Measurement in vacuumS2

99.99999.99899.99799.99699.99599.99499.99399.99299.99199.990620

930

T [ppm]LL for 3 Wavelengths. T (650nm)
100

Measurement+theory in vacuum

750

S2

90
80
70
60
50
40
30
20
10
0
620

m

ea

s u rethementwavelength [nm]LL for 3 Wavelengths. T (880nm)
630

or

640

650

660

670

680

690

100

700
S2

90
80
70
60
50
40
30
20
10
0
830

wavelength [nm]
840

850

860

870

880

890

PiecesImperfections

42
2

5 / 1 x 0.006
5 / 1 x 0.01
5 / 1 x 0.025

900

910

920

Measurement in vacuum

700

y

650

T [ppm]600

T [ppm]R [%]wavelength [nm]LL for 3 Wavelengths. R (650nm)

Calculation (theory)

S2

90
80
70
60
50
40
30
20
10
0
550

930

Defect distribution within 1 batch (up to 8 pieces)131

Standard Items from Stock
Beam Expanders

Beam Expanders
fCX
fCC

distance (d)

R

f =_
n-1

|fCX| - |fCC| = dmagniﬁcati

on factor:

Focus
(F)

1 million

Concave Lens
(CC)

Convex Lens
(CX)

Lens Matrix
Magnification / reduction factor with distance d
ROC of
CC Lens
CX 125

ROC of CX Lens
CX 150

CX 175

CX 2001.		 Select an magnification or reduction factor from the table on
the left. For your convenience the lens distance is also given in
the table.

CC 1001.25(d ≈ 55 mm)

1.5
1.75
2
(d ≈ 110 mm) (d ≈ 165 mm) (d ≈ 220 mm)

CC 75

1 2/3
2
2 1/3
2 2/3
(d ≈ 110 mm) (d ≈ 165 mm) (d ≈ 220 mm) (d ≈ 275 mm)

CC 50

2.5
3
3.5
4
(d ≈ 165 mm) (d ≈ 220 mm) (d ≈ 275 mm) (d ≈ 330 mm)

2.		 Find the corresponding ROC (radius of curvature) for bothlenses. The concave lens (CC) is indicated on the left, theconvex lens (CX) on the top.

CC 25

5
6
7
8
(d ≈ 220 mm) (d ≈ 275 mm) (d ≈ 330 mm) (d ≈ 390 mm)

3.		 Select the two lenses for your preferred spectral range fromthe tables below.

Magnification and reduction factor depending on the ratios of the radii of curvature of concave (CC) and convex (CX) lens, distance d is calculated for Fused Silica@920 nm (with n = 1.4515)

Lenses 0°, 800 nm

Lenses 0°, 1 000 nm

wavelength [nm]
600

650

700

750

800

850

900

950

Calculated reflection for each side

1000

2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0

R [%]

2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0

Coating 160881
AR (0°, 900 – 1 100 nm) < 0.5 %R [%]Coating 160878
AR (0°, 725 – 875 nm) < 0.5 %wavelength [nm]
850

900

950

1000

1050

1100

1150

1200

Substrate Dimensions [mm] No.

Imperfections

Item #

Price

Substrate Dimensions [mm] No.

Imperfections

Item #PriceØ 25.0 | te 6.35 | CC 25Ø 25.0 | te 6.35 | CC 50
Ø 25.0 | te 6.35 | CC 75Ø 25.0 | te 6.35 | CC 100
Ø 50.0 | tc 6.35 | CX 125
Ø 50.0 | tc 6.35 | CX 150
Ø 50.0 | tc 6.35 | CX 175
Ø 50.0 | tc 6.35 | CX 200

Øe 15 | 5/ 1 x 0.04
Øe 15 | 5/ 1 x 0.04
Øe 20 | 5/ 1 x 0.04
Øe 20 | 5/ 1 x 0.04
Øe 30 | 5/ 2 x 0.04
Øe 30 | 5/ 2 x 0.04
Øe 30 | 5/ 2 x 0.04
Øe 30 | 5/ 2 x 0.04

160716160717160718160719160720160721160722160723

438 €
390 €
360 €
348 €
864 €
852 €
840 €
828 €

Ø 25.0 | te 6.35 | CC 25Ø 25.0 | te 6.35 | CC 50
Ø 25.0 | te 6.35 | CC 75Ø 25.0 | te 6.35 | CC 100
Ø 50.0 | tc 6.35 | CX 125
Ø 50.0 | tc 6.35 | CX 150
Ø 50.0 | tc 6.35 | CX 175
Ø 50.0 | tc 6.35 | CX 200

Øe 15 | 5/ 1 x 0.04
Øe 15 | 5/ 1 x 0.04
Øe 20 | 5/ 1 x 0.04
Øe 20 | 5/ 1 x 0.04
Øe 30 | 5/ 2 x 0.04
Øe 30 | 5/ 2 x 0.04
Øe 30 | 5/ 2 x 0.04
Øe 30 | 5/ 2 x 0.04

160704160707160710160711160712160713160714160715

438 €
282 €
360 €
348 €
864 €
852 €
840 €
828 €

L1a
L1b
L1c
L1d
L2a
L2b
L2c
L2d

L1a
L1b
L1c
L1d
L2a
L2b
L2c
L2d

Note: The AR coatings shown here are options. On request, LAYERTEC offers the anti-reflective quartz glass lens set for any
wavelength in the range of 190 – 2 200 nm (except 1 370 – 1 420 nm).
132

1250

Calculated reflection for each side

Precision Optics

Precision Optics

Chapter Index
How to Specify Substrates..............................................134
Material...............................................................................134
Shape...................................................................................134
Size......................................................................................134
Tolerances............................................................................134
Surface Form Tolerances.......................................................135
Coating Stress......................................................................135
Defects.................................................................................135
Standard Quality Substrates............................................136
Standard Specifications........................................................136
Substrate Materials.........................................................138
Fused Silica..........................................................................138
Calcium Fluoride...................................................................139
Sapphire...............................................................................139
Yttrium Aluminum Garnet....................................................140
Various Substrate Materials for UV, VIS and NIR/IR Optics.....141
Optical Fabrication Methods...........................................142
Manufacturing Technologies................................................142
Plane Optics.........................................................................143
Spherical Optics...................................................................143
Cylinder Optics.....................................................................144
Aspheres & Free Forms.........................................................145
Special Surfaces....................................................................148
Large Scale Optics................................................................149
Scanning Mirrors & Lightweight Structures...........................150
Etalons & Waveplates...........................................................151
Measurement Tools for Testing Substrates......................152
Surface Form Deviations.......................................................152
Surface Form Measurement..................................................152
Surface Roughness Measurement.........................................153
Measurement Systems for Testing Substrates.......................154

133

Precision Optics
How to Specify Substrates

How to Specify Substrates
Price and quality of substrates are determined by material, shape, size, tolerances and polishing quality.

Material
The first decision is the choice of the substrate material. It should be free of absorption for all wavelengths of high transmittance. If notransmittance occurs, a low-cost material can be used, e.g. Borofloat® (SCHOTT AG), for metallic mirrors. With respect to the surface form
tolerance, a low thermal expansion is beneficial.

Shape

ε

plane
(pl/pl)plane/
concave(pl/CC)plane/
convex(pl/CX)

concave/convex(CC/CX)wedge
in [arcmin]or [deg]

The shape must be specified for both sides separately. All combinations of plane, convex and concave surfaces are possible. This isalso the case for wedges, e.g. 30 arcmin, which can be applied to
any kind of surface, plane as well as convex or concave. For curved
substrates there are different conventions for the sign of the radiusof curvature. Sometimes “+” means convex and “-” means concave. Other users refer to the direction of light propagation. In thiscase, “+” means “curvature in the direction of propagation” and“-” means “curvature against the direction of propagation”. Please
specify concave or convex in words or using the acronyms CC or
CX to avoid confusion.

Figure 1: Conventions for the specifications of the shape of different typesof substrates (schematic drawing)Size
The main decision should be about the size of the substrate, i.e. edge length or diameter. Small diameters are more favorable for production. The sagitta heights become lower, so it is easier to achieve a good form tolerance. Although often denoted otherwise in opticaldesigns, LAYERTEC specifies the thickness as the maximum thickness of the substrate, i.e. the center thickness for plano-convex substrates
and the edge thickness for plano-concave substrates. Consequently, the thickness of a wedged plate is measured on the thicker side.
In order to achieve a good form tolerance, the ratio of diameter and thickness should be considered. As a rule of thumb the thickness
should be at least one fifth of the diameter. Of course, other ratios are possible but production costs and therefore prices increase as well.

Tolerances
Besides size and material, the tolerances are most important for manufacturing costs and thus pricing. Of course, the optics must fit into
the mount, so the diameter should not be larger than specified. Thus, the most common specification is Ø = X mm (+0 mm/-0.1 mm).
In contrast, the thickness is generally free in both directions. LAYERTEC usually specifies it with a tolerance of ± 0.1 mm. There is a lot ofconfusion about the specification of wedge, parallelism and centering. Please note that wedge and parallelism describe the angle between
the optical surfaces while centering describes the angle between the optical surfaces and the side surfaces. LAYERTEC standard substrates
have a parallelism better than 5 arcmin. Specially made parallels may have a parallelism lower than 10 arcsec. Standard wedged substrates
have wedges of 0.5° or 1°. Larger wedge angles are possible depending on the substrate size. In general, the 90° angle between opticaland side surface has a precision of 20 arcmin. Centering is an additional optics processing step which improves this accuracy to a few
arcmin.
Curved substrates can be described using the same nomenclature. It should be distinguished between mirrors and lenses. The side surfacesof mirror substrates are parallel. Nevertheless, the direction of the optical axis can be inclined with respect to the side surfaces. After centering, the side surfaces are parallel to the optical axis.

134Precision Optics
How to Specify Substrates

Surface Form Tolerances
The surface form tolerance is usually measured by interferometers and is specified in terms of the reference wavelength (λ = 546 nm if nototherwise stated). In order to avoid confusion, it is necessary to clearly distinguish between flatness, power and irregularity. In the following, flatness and irregularity shall be explained for a plane surface. Generally speaking, every real surface is more or less curved. Imagine
that the “peaks” and “valleys” of a real surface are covered by parallel planes (see figure 2). The distance between these planes is called
the flatness. This flatness consists of two contributions. The first contribution is a spherical bend of the surface, which may be describedby a best fitted sphere to the surface. With respect to an ideal plane, the sagitta of this curvature is denoted as power. This spherical bend
does not affect the quality of the reflected beam. It just causes a finite focal length. The second contribution is the deviation from the best
fitted sphere, which is named irregularity. This is the most important value for the quality of the beam.

λ/10

λ/10

λ/4

λ/4

The standard ISO 10110 provides a sufficient method for specifying the surface form tolerance. Having the best comparability
with the measurement results, all values are specified as numbersof interference fringes, with 1 fringe = λ/2. In technical drawings
according to ISO 10110, the surface form tolerance is allocated as
item number 3/: 3/ power (irregularity)
Example: A slightly bent (λ/4) optics which is regular (λ/10) would
be specified as follows:

flatness of λ/10

spherical bending(power of λ/4)

irregularity of λ/4,
but transmitted
wavefront of λ/10

3/ 0.5 (0.2)

Figure 2: Schematic drawing for the explanation of substrate properties

Using the optics only for transmittance (e.g. laser windows), power as well as irregularity do not matter. A transmitted beam is not affected
if the optics has the same thickness all over the free aperture. The influence of thickness deviations on the transmitted beam is defined in asimilar way as the flatness. It is also measured in parts of the reference wavelength and called “transmitted wave front” (13/). For instance,
the window in figure 2 has a flatness of λ/4 but a transmitted wave front of λ/10.

Coating StressThin substrates cannot withstand the coating stress. The coating will cause a spherical deformation (for rotationally symmetric coatings).
This means that a finite sagitta or power occurs. In case of circular substrates, the irregularity is not affected by this issue. Even if power
deviation is considered, the quality of a beam under normal incidence is not affected.

Defects
ISO 10110 is an international standard for the description of optical elements. According to ISO 10110, maximum permissible surface imperfections can be specified as item number 5/ in technical drawings. It allows for dimensional as well as visibility specification of surface
imperfections, the latter being based on the MIL-O-13830 standard.
In the visibility specification, scratches and digs have to be distinguished. The scratch number refers to the visibility of the biggest scratch
compared to the corresponding one on a norm template. “10” is the smallest scratch on this template. Thus, better qualities cannot be
specified legitimately. Moreover, the visibility specification does not specify a directly measured but an apparent scratch width. The number
is interpreted as tenths of a micron or as microns. In contrast, the dig number can be determined easily. The numerical value is equal to the
maximum apparent dig diameter in hundredths of a millimeter. One maximum-size dig per 20 mm clear aperture is allowed.
In the numerical specification, the grade number is the side length in millimeters of a square area which is equivalent to the total defectarea. So, 1 × 0.025 describes a surface defect area of 625 μm². Additionally, scratches of any length are denoted with a leading L. A longscratch, i.e. exceeding 2 mm of length, with a width of 4 microns would be specified as L 1 × 0.004.
All these explanations are very simplified. For a detailed specification please read the complete text of the relevant standard.

Please Note
There is no direct conversion between visibility and dimensional specification. All specifications in this catalog are dimensional. The
mentioned scratch/dig values are rough approximations.

135

Precision Optics
Standard Quality Substrates

Standard Quality Substrates
The precision optics facility of LAYERTEC produces plane and spherically curved mirror substrates, lenses and prisms of Fused Silica, opticalglasses like N-BK7^®^ and some crystalline materials, e.g. calcium fluoride and YAG. In the following you can find information on thespecifications of our standard substrates. Please do not hesitate to contact us also for other sizes, shapes, radii and materials or for special
components. For cylindrical, aspherical and free form optics see page 144 and 145.

Standard Specifications
t min

Ø

Ø
ε
t max

t

r

r
Ø

Ø

te

tc
te
tc
t

edge thickness [mm]center thickness [mm]thickness [mm]øεdiameter [mm]wedge [°]

Figure 1: Standard specifications of optics

Materials• Fused Silica: Corning 7980® or equivalent• Fused Silica for high power applications in the NIR:
Suprasil® 300/3001/3002 / Corning 7979® or equivalent• UV Fused Silica (excimer grade): SQ1 E-193® and
SQ1 E-248®
• IR Fused Silica: Infrasil 302® or equivalent• ULE®
• Zerodur®
• N-BK7® or equivalent• CaF2: single crystal, randomly oriented, special orientations on request, excimer grade (248 nm and 193 nm) on
request• Saphir: single crystal, C-cut• YAG: undoped, single crystal, randomly oriented• Further information on the substrate materials most frequently used can be found on page 138 ff.
Plane substrates, parallels and wedges• Standard plane substrates: wedge < 5 arcmin• Standard parallels: wedge < 1 arcmin or wedge < 10 arcsec• Standard wedges: wedge = 30 arcmin or wedge = 1 deg

136

Plano-concave and plano-convex substrates• Standard radii: 25, 30, 38, 50, 75, 100, 150, 200, 250,
300, 400, 500, 600, 750, 1000, 2000, 3000, 4000,
5000 mm• Other radii on request
Dimensions• Fused Silica, ULE®, Zerodur®: diameter 3 … 600 mm• Calcium fluoride, sapphire: diameter 3 … 50.8 mm• YAG: diameter 3 … 38.1 mm• Rectangular substrates and other diameters available on
requestTolerances• Diameter: +0 mm, -0.1 mm• Thickness: ± 0.1 mm• Clear aperture: central 85 % of dimension• Chamfer: 0.2 … 0.4 mm at 45°

Precision Optics
Standard Quality Substrates

Table 1: Surface form tolerances (reference wavelength: 546 nm)

Material

ShapeStandard Specification

On Request

Fused Silica

plane
spherical

λ/10
λ/10 reg.

λ/30
λ/30 reg. (Ø < 51 mm)

ULE® und Zerodur®

planespherical

λ/10
λ/10 reg.

λ/30
λ/30 reg. (Ø < 51 mm)

N-BK7®

plane
spherical

λ/10
λ/10 reg.

λ/30
λ/30 reg. (Ø < 51 mm)

CaF2plane Ø < 26 mm
plane Ø < 51 mm
spherical

λ/10
λ/4
λ/4 reg.

λ/20
λ/20
λ/20 reg. (Ø < 51 mm)

Saphir

λ/10

λ/30

YAG

plane
spherical

λ/10
λ/8 reg. (typically λ/10 reg.)

λ/30
λ/30 reg. (Ø < 51 mm)

Si

plane
spherical

λ/10
λ/8 reg. (typically λ/10 reg.)

λ/20
λ/20 reg. (Ø < 51 mm)

Table 2: Surface imperfection tolerances

Material

Standard Roughness*

Standard Specifications

On Request*

Fused Silica< 0.2 nm

5/ 1 × 0.025 L1 × 0.004
Scratch-Dig 10-3

< 0.15 nm

5/ 1 × 0.016 L × 0.0005
Scratch-Dig 5-1

ULE®

< 0.2 nm

5/ 3 × 0.025 L1 × 0.004
Scratch-Dig 10-5

< 0.2 nm

5/ 1 × 0.016 L1 × 0.0005
Scratch-Dig 5-1

Zerodur®

< 0.4 nm

5/ 2 × 0.040 L1 × 0.004
Scratch-Dig 10-5

< 0.3 nm

5/ 2 × 0.025 L1 × 0.0010
Scratch-Dig 10-3

N-BK7®

< 0.3 nm

5/ 1 × 0.040 L1 × 0.004
Scratch-Dig 10-5

< 0.2 nm

5/ 2 × 0.025 L1 × 0.0010
Scratch-Dig 10-3

CaF2

< 0.3 nm

5/ 1 × 0.04 L5 × 0.006
Scratch-Dig 20-5

< 0.2 nm

5/ 2 × 0.025 L5 × 0.004
Scratch-Dig 10-2

Saphir

< 0.3 nm

5/ 1 × 0.025 L10 × 0.004
Scratch-Dig 20-3

< 0.2 nm

5/ 1 × 0.016 L1 × 0.0010
Scratch-Dig 10-2

YAG

< 0.2 nm

5/ 1 × 0.025 L2 × 0.004
Scratch-Dig 20-3

< 0.2 nm

5/ 1 × 0.016 L1 × 0.0005
Scratch-Dig 5-1

Si< 0.3 nm

5/ 3 × 0.025 L10 × 0.004
Scratch-Dig 10-5

< 0.2 nm

5/ 3 × 0.016 L3 × 0.0005
Scratch-Dig 5-1*

All specifications according to ISO 10110 (Ø 25 mm). The mentioned Scratch-Dig values are approximately equivalent to MIL-O-13830
which was incorporated into ISO-10110.
Valid for measurements with optical profilometer taking into account spatial structures in the 1 – 70 µm.

Please note: Scratches wider than 1 µm µm are guaranteed not to occur. Specifications according to ISO 10110 are not possible because
scratch widths down to 0.3 µm µm can not be measured as would be required.

137

Precision Optics
Substrate Materials

Substrate Materials
Fused Silica
General Information
Measurement
100
90
80
70
60
50
40
30
20
10
0

Suprasil 300®

Corning 7980®

b

Infrasil 301®

Measurement
95

Corning 7980®

Suprasil 300®

Infrasil 301®

94
T [%]

T [%]

a

93
OH

92

OH

OH

91
0

500

1000

1500

2000

2500

3000

90

3500

900

1000

1100

wavelength [nm]

1200

1300

1400

1500

wavelength [nm]Figure 1: Transmittance spectrum of various types of Fused Silica, 6.35 mm thick (a) with close up of Fused Silica absorption band (b)Fused Silica (SiO2) is one of the most important materials in the optical industry. For the production of high-performance optics, Fused Silica
of particularly high quality is required. The purity of naturally occurring quartz is often insufficient for this purpose, so that synthetic quartz
glass is used. SiO2 corresponds in its chemical composition to the simplest form of glass and is its most stable modification. Fused Silica
has a refractive index of 1.46 (for λ = 500 nm) and an Abbe number of 67.70. It transmits light from 180 nm to about 3 µm. Absorption
bands also occur within this transmission range due to the hydroxyl groups it contains. Fused Silica with high OH content has to be used
for UV application whereas “low-OH” Fused Silica should be used for transmissive components in the 940 nm, 1390 nm and 2 µm – 3 µm
wavelength range.

Production
For the production of an amorphous (bubble- and streak-free) Fused Silica without impurities, there are different approaches that influence
the final product in terms of optical specifications (see table).
Table 1: Optical specifications of Fused Silica depending on production technology

Separation/Source
material

OH

Cl

Cations

UV- Edge 50 %transmission

Examples for trademarksElectrofusion of quartz
sand or rock crystal< 20 ppm

0 ppm

50 – 300 ppm

220 nmInfrasil®
Vitreosil-IR®

Flame melt mostly
from rock crystal

200 – 500 ppm

0 ppm

10 – 50 ppm

210 nmHomosil®
Optosil®

Flame hydrolysis ofsilane or with silicontetrachloride

600 – 1200 ppm

50 – 100 ppm< 1 ppm

170 nmCorning 7980®
Suprasil 1®
J-Plasma SQ®

Silicon tetrachloride
in hydrogen/oxygenflame< 20 ppm< 200 ppm

1 – 2 ppm

170 nmSuprasil 3001®

Properties and Applications
The most important properties of Fused Silica, which are essential for LAYERTEC´s products:• High chemical purity• Durability• Heat resistance• Low coefficient of thermal expansion at high temperatures• High softening temperature• High transparency over a wide spectral range (UV-IR)• High radiation resistanceIn the short wavelength and visual range Fused Silica (with higher OH content, e.g. Corning 7980®) is used. Excimergrade materials are used
for transmissive optics for UV high power lasers. Standard Fused Silica is of limited use for transmissive optics in the infrared range. Naturally occurring Fused Silica (e.g. Infrasil®) and specially manufactured Fused Silica (e.g. SUPRASIL 3001/3002/300®, …) have an extremely
low OH content (< 20 ppm) and can therefore also be used for the infrared wavelength range to approximately 3 µm.
138Precision Optics
Substrate Materials

Calcium Fluoride

T [%]General Information
100
90
80
70
60
50
40
30
20
10
0

Measurement

150

300

5000

7000

9000

11000

wavelength [nm]Calcium fluoride (CaF2) is an optically homogeneous crystal material with a cubic structure. It is also called fluorspar and occurs naturally, but does not reach the purity required for UV applications inlithography or medicine. Crystal growth of CaF2 from synthetically
produced raw materials can eliminate the inclusion of impurities.
In addition, the refractive index of 1.43 (for λ = 500 nm) can always be precisely adjusted and the homogeneity achieved exceedsthat of glass. The Abbe number is 94.996 in all crystal directions.
Calcium fluoride has a wide transmission range from 0.125 µm to
8 µm. The optical properties enable better correction of chromaticaberration than glass materials in the spectral range from VIS to
NIR.

Figure 2: Transmittance spectrum calcium fluoride (3 mm thick)

Production
Fluorspar is extracted by open pit and deep mining. Due to the impurities it contains, it must first be processed. In this process, the starting
material is crushed and purified by a multi-stage floatation process. Pure calcium fluoride is obtained by the reaction of hydrogen fluoride
or hexafluorosilicic acid with calcium carbonate.

Properties and Applications
The mechanical properties of CaF2 make machining optics a challenge. The material is very soft (Mohs hardness 4) and is therefore
scratched easily. It can be easily cleaved (cleavage level 5 in plane). Due to its high coefficient of thermal expansion, there is a risk of cracking if machined quickly or if the temperature changes unevenly. In addition, it cannot be cemented to other materials. Uncoated polishedsurfaces react with atmospheric moisture and become hazy after prolonged exposure as micro-roughness increases. This creates stray lightand reduces contrast.
Because of the high coefficient of thermal expansion, fluoride substrates should also be coated with fluoride layers if possible. Furthermore,heating and cooling rates must be observed to prevent cracking of the substrates.
Calcium fluoride is used at LAYERTEC for special applications in the ultraviolet range. It is processed into laser mirrors, output couplers,beam splitters, lenses, windows for excimer lasers and frequency-multiplied solid-state lasers, among others. In fluorine environment, thelifetime of CaF2 optics is significantly longer than that of other materials.
Due to the mechanical properties, it should be ensured in the application that the products are not subject to temperature fluctuations
and temperature gradients. The optics should be stored with desiccant and under constant conditions. Therefore, the packaging shouldbe opened only shortly before use.

Sapphire
General Information
The sapphire (Al2O3) is a variation of the mineral corundum. For the
optical industry, the synthesized form is used. Sapphire is an anisotropic material with a rhombic-hexagonal structure and shows different optical properties depending on the crystal axis and angle
of incidence. These must be taken into account for the calculationof the final products. Sapphire is transparent in the range from
180 nm to about 4 µm. The refractive index of the material is 1.77
– 1.78 (for λ = 500 nm).

T [%]Measurement
100
90
80
70
60
50
40
30
20
10
0

200

2300

4400

6500

wavelength [nm]Figure 3: Transmittance spectrum of sapphire (3 mm thick)139Precision Optics
Substrate Materials

Production
For the production of very high quality sapphires the Heat Exchanger Method (HEM) is used. This enables the production of large crystals.
A heat exchanger takes care of the heat dissipation. In the process, the crystal growth region forms a temperature gradient. By controlling
the gas volume in the heat exchanger and changing the heating power, this gradient is maintained. The crystal can now grow slowly fromthe bottom to the top.
The Verneuil method is applied to produce sapphire boules. These are also called stalagmites. Flame fusion is used in this process. Purealuminum oxide is melted at nearly 2000°C. Due to gravity, liquid Al2O3 falls onto a seedling and gradually forms a boule. The growth of asapphire sphere sometimes takes several days.

Properties and Applications
The most important properties of sapphire for use as a substrate material:• Extreme hardness (Mohs hardness 9), can only be further
processed with a few materials (e.g. diamond)• High chemical resistance• Scratch resistance• Wide transmission range• Very good thermal conductivity

Due to its optimum thermal conductivity and particularly good transmission properties in the mid-infrared range, sapphire is used at
LAYERTEC primarily for high-performance components in the spectral range of 2 – 3 µm.

Yttrium Aluminum GarnetGeneral Information
Yttrium aluminum garnet (Y3Al5O12 or YAG) is a crystal material
with cubic structure, which is produced synthetically. The refractive index is 1.84 (for λ = 500 nm). It indicates good transmission
behavior in the range from 0.25 µm to 4 µm. Undoped YAG is freeof absorption in the range of 2 – 3 µm, whereas Fused Silica showshigh absorption bands exactly here due to the higher proportionof OH groups.

T [%]Measurement
100
90
80
70
60
50
40
30
20
10
0

200

1200

2200

3200

4200

5200

6200

wavelength [nm]Figure 4: Transmittance spectrum of YAG undoped (3 mm thick)

Production
The YAG crystal is produced mainly by the Czochralsky method. In this process, the already purified starting material is heated to a few
degrees above the melting point without spontaneous nucleation. If a small single crystal is now immersed and moved upwards by slowly
rotating and pulling it without breaking contact with the melt, single crystals of more than 300 mm in length and up to 100 mm in diameter are produced.

Properties and Applications
YAG has several properties which are advantageous for the manufacturing of high performance optics. Its chemical and mechanicalresistance are similar to sapphire. However, due to its lower Mohs hardness of 8.5, YAG is easier to machine. The crystal’s high thermal
conductivity and low absorption losses allow it to withstand high laser energies. The YAG crystal in doped form is also well suited for use
as an active medium for lasers (Yb:YAG 1030 nm, Nd:YAG 1064 nm, Tm:YAG 2.01 µm, Ho:YAG 2.1 µm, Er:YAG 2.94 µm).
At LAYERTEC undoped YAG is used especially in the mid-infrared range (MIR) up to ≈ 4 µm. It has the advantage over sapphire that it
lacks birefringence and therefore no attention has to be paid to crystal cut and angle of incidence. In the in-house optics production YAG
substrates are manufactured in different sizes both as flat parts and as curved substrates or lenses.

140

Precision Optics
Substrate Materials

Various Substrate Materials for UV, VIS and NIR/IR Optics
Table 2: Specifications of various substrate materials

Wavelength
range free ofabsorption

Fused Silica(UV)

Infrasil®1)

YAG (undoped)

Sapphire(C-cut)CaF2

N-BK7®2)Si

190 nm –2.0 μm 3)

300 nm – 3 μm

400 nm – 4 μm

400 nm – 4 μm

130 nm – 7 μm

400 nm –1.8 μm

1.4 – 6 μm

Refractive Index
at
200 nm1.55051

300 nm1.48779

500 nm1.462431.48799

1.84501.775

1.43648

1.52141 μm

1.450511.450421.81971.756

1.42888

1.50751.419411.78551.71

1.417853.4381

1.624

1.39896

3.42733 μm

1.495161.454035 μm
9 μm

1.32677

Absorbing in the
3 μm region

yes

Absorbing in the
940 nm region

For high power applications at 940 nm the Fused Silica types SUPRASIL 300®1) and SUPRASIL 3001/3002®1) are recommended.

Birefringence

no

no

no

yes

no 4)

no

no

Thermal expansion coefficient[10–6 K-1] 5)(0 – 20°C)

0.5

0.5

7

5

18

7

2.6

Resistanceagainst temperature gradientsand thermal
shock

high

high

high

high

low

mediumlow

400 nm

98

98

240

150

68

120

800 nm

36

36

97

58

28

45

1064 nm

16

16

61

29

17

22

1500 nm

-22

-22

13

-25

1.9

-19

2000 nm

-100

-100

-59

-120

-21

-99

400 nm

30

30

75

47

19

41

800 nm

27

27

57

42

16

32

1064 nm

44

44

71

65

21

49

1500 nm

130

130

140

180

46

140

2000 nm

450

450

360

530

120

460

yes

no

no

no

yes

no

GDD fs² per mm

TOD fs3 per mm

1)
2)
3)
4)
5)

Registered trademark of Heraeus Quarzglas GmbH & Co. KG
Registered trademark of SCHOTT AG
Absorption band within this wavelength range, please see transmittance curve
Measurable effects only in the VUV wavelength range
Please note that different authors in the literature are inconsistent. Moreover, the thermal expansion coefficient of crystals may depend also on crystal
orientation. Thus, the value given here are approximated.
All values are for informational purposes only. LAYERTEC cannot guarantee the correctness of the values given.

141

Precision Optics
Optical Fabrication Methods

Optical Fabrication Methods
Manufacturing Technologies
LAYERTEC has its own in-house precision optics facility where substrates with almost all geometries are manufactured. The optics are
finished in our coating department according to individual customer requirements.

Traditional and Alternative Fabrication Methods

Figure 1: Conventional polishing of plane surfaces

Figure 2: Conventional polishing of spherical optics

For the shaping of LAYERTEC optics, the production technologies grinding, lapping and polishing are mainly applied. Grinding is machining
with geometrically undefined cutting edge. The cutting edges are irregularly arranged. The tool movement is rotary. The grain is bound in
the tool. Lapping and polishing also belong to the machining processes with a geometrically undefined cutting edge. However, these arereferred to as material removal by loose grains. The material is removed by a rolling movement of the lapping or polishing grains over the
workpiece surface. From grinding to lapping to polishing, the grain sizes of the tools decrease. Each grain leaves surface imperfections in
the order of the grain diameter during machining. The material removal of the next finer tool must be at least large enough to eliminate
the surface defects of the previous one.
Besides the polishing of standard materials, LAYERTEC supports the polishing of various types of crystals such as YAG, KTP, LBO or BBO.
This polishing technology also enables the careful handling and processing of small crystal sizes or extraordinary forms.

Ultrasonic Cleaning

Figure 3: Ultrasonic cleaning

Ultrasonic cleaning represents the link between optics processing
and coating in the production process. All substrates manufactured, purchased by LAYERTEC or provided by the customer must
be absolutely clean before coating. Machining residues from optics production must be removed and the coating requirements forclean substrates must be met. LAYERTEC currently has 6 different
ultrasonic cleaning systems for different requirements (e.g. crystal
cleaning, pre-cleaning, fine cleaning, geometry dependent). The
type of contamination determines the arrangement of the cleaningbaths. Due to many years of experience in the field of ultrasoniccleaning, LAYERTEC has a broad knowledge base.

Material properties of individual cleaners, temperatures as well as drying processes are always taken into account. Tailor-made solvents andthe appropriate arrangement of cleaning baths can be used to deal specifically with a wide range of contaminants (emulsions, polishing
agents, particles, fingerprints, salts, oils, greases, wax, water, paints, polymers, inks, etc.).

Ultrasonic Drilling
Using ultrasonic drilling, LAYERTEC is able to manufacture holes
and other structures in a variety of forms and sizes in glass, ceramics or crystals in a low-tension way. Coated as well as uncoatedoptics may be processed.

142

Figure 4: Substrate with conical hole, produced by ultrasonic drillingPrecision Optics
Optical Fabrication Methods

Plane Optics

Figure 5: Substrates for 45°-mirrors on multiple block

Figure 6: Lapped plane substrates on multiple block

Plane optics can be manufactured efficiently by using proven techniques of surface grinding, lapping and polishing.
Planar substrates are manufactured with diameters from 1.5 mm to 600 mm (round) or with edge lengths from 1 mm to 1200 mm (rectangular). Substrates down to a minimum thickness of 0.08 mm and any wedge can be produced. Special external geometries according tocustomer requirements are also possible.
Surface roughness of < 0.2 nm (usually measured for spatial structures in the range of 1 µm – 70 µm) is possible. Depending on the application wavelength, both defined and optimized surface roughnesses can be manufactured.
Plane optics are made from the following materials:• Fused Silica• Zerodur®

• Crystalline Quartz• Silicon• YAG/LuAG• BBO/LBO/KTP• CaF2• All commercially available optical glasses• ULE®

• Toxic substrate materials, like ZnSe are not processed

Spherical Optics

Figure 7: Grinding process on CNC machine

Figure 8: Spherical optics on multiple block

At LAYERTEC, single and double-sided curved substrates with convex or concave shapes are manufactured. The processing of a variety of
optical glasses (e.g. Fused Silica, N-BK7®, ULE®) and crystals (e.g. Si, YAG, CaF2) is possible. Available radii of curvature vary from 5 mm to
100 000 mm. Manufacturing of substrate diameters from Ø = 3 mm to Ø = 600 mm (see also Large Optics on 148) is possible.
For Fused Silica, the following specifications can be achieved:• Surface form deviations:• Clear aperture up to 85 % of substrate diameter• Further test areas on request• 3/ -(0.2) (λ/10)• 3/ -(0.1) (λ/20) on request• Roughness Sq = 0.25 nm (for measurements with an opticalprofilometer taking into account spatial structures in the1 – 70 µm range)• Roughness Sq < 0.2 nm on request

Depending on the geometry, a centering accuracy of 1 arcmin and a radius tolerance of ± 0.5 % can be achieved. We handle projects withspecial requirements on request.
143Precision Optics
Optical Fabrication Methods

Cylinder Optics

Figure 9: Polishing machine for cylinder optics

Figure 10: Large cylindrical lens

At LAYERTEC, cylindrical lenses can be manufactured in both concave and convex shapes, with a radius of curvature on one or both sides.
Round or angular component shapes are possible. Cylindrical lenses can be made of different materials (Fused Silica, N-BK7®, SF6, CaF2).
Cylindrical lenses with very small concave and convex radii in the order of r ≥ 7 mm can be manufactured. The production of radii up tor = 1900 mm is possible with fit irregularities of λ/20.
With suitable metrology (e.g. white light interferometry, cylinder interferometry) the surface specifications for shape and polishing quality
can be ensured.
Table 1: Specifications of cylinder optics of Fused Silica an CaF2

Fused Silica

CaF2

Clear aperture

80 %

80 %

Surface form tolerance (irregularity)

standard λ/4
on request λ/20

standard λ/4
on request λ/10

25 mm × 25 mmstandard 5/ 1 × 0.04
on request 5/ 1 × 0.025

12.7 mm × 12.7 mmstandard 5/ 1 × 0.063
on request 5/ 1 × 0.04

Surface imperfection tolerance

Specifications for other sizes on request

LAYERTEC’s cylinder optics are used in aerospace, display manufacturing or laser generation, among others.

144

Precision Optics
Optical Fabrication Methods

Aspheres & Free Forms
Plane and spherical optics can be efficiently manufactured by using traditional techniques of area grinding and polishing. The tool always
works on a significant fraction of the substrate area at once. However, it is hardly possible to manufacture surface geometries that differ
from regular forms like planes, spheres or cylinders. Using ultra precision CNC machinery, surfaces can be processed zonally, i.e. the tool
works on one point at a time. The possible surface forms and tolerances are only limited by the precision of the machine and the measurement equipment. In contrast to the areal techniques, zonal processing usually works with a single piece per run only. Non-spherical optics
can be divided into three categories: rotationally symmetric, off-axis and free form optics.

Rotationally Symmetric Non-Spherical Optics (Aspheres)
Although the term “asphere” may stand for any non-spherical optics, it is often restricted to rotationally symmetric optics. They are described by the following equation (cf. ISO 10110):r²

z (r) =r²
1 − (1 + K )
R²

R 1+

z = sagitta+ A₃r ³ + A₄r ⁴ + . . .

K = conic constantr = distance from axis, r =x² + y ²

R = radius of curvature
A i = aspheric coefficients

Neglecting the aspheric coefficients leads to a profile of conic sections:• Sphere: k = 0• Ellipse: -1 < k < ∞• Parabola: k = -1
• Hyperbola: k < -1
Table 2: Production dimensions and tolerances

opening diameter
inspection range

total thickness

total diameter

sagitta heightz

centering error

centerthicknessrtilting error

Figure 11: Profile of an aspheric mirror

Dimension

Tolerances

Total Diameter

25 – 560 mm< 0.1 mm

Inspection Range< 550 mm

Total Thickness< 100 mm

Sagitta< 50 mmCentering Error< 50 mm

Tilt Error< 30’’

Surface form tolerance (P-V)

λ/4(λ/10 on request)

Roughness*< 0.3 nm*

Figure 12: Parabolic substrate in production process, before (l.) and after
lapping and polishing (r.)< 0.1 mm

Valid for measurements with optical profilometer taking into accountspatial structures in the 0.65 – 55 µm range

Figure 13: Robotic cleaning and inspection

145Precision Optics
Optical Fabrication Methods

Off-Axis Surfaces
An off-axis surface can be seen as a section of a bigger on-axis surface. The focal point still is on the original optical axis but not the centerof the section. Instead, it is located off-axis. Off-axis surfaces derived from aspheres are described by the mentioned equation, the off-axis
distance a and/or the off-axis angle α.
The focal length of the parent parabola (fparent) is measured fromthe vertex on the optical axis. For the off-axis parabola (OAP), an
effective focal length (feff) is introduced. The off-axis distance ismeasured from the optical axis to the middle of the OAP. The radius R denotes the radius of curvature in the vertex of the parent
parabola. The conic constant k is -1.

z
ø

feff

In principle, an off-axis substrate can always be mechanically cut
from an on-axis substrate. The alternative way is direct manufacturing (parallel configuration). Depending on the size and tolerances, both ways are possible.

αfparent

focal
point

vertexr

Basically, LAYERTEC’s off-axis surfaces are manufactured in the
direct way. Manufacturing from the parent parabola is currently
limited to Ø = 300 mm and is only carried out on request.

afparent focal length of parent parabola
effective focal lengthfefføsubstrate diameterαazoff-axis angle
off-axis distance
optical axis

Figure 14: Schematic drawing of an off-axis parabola (OAP)

Please provide the following specifications when making inquiries:• Geometry data
• Tested area
• Focal length (effective or parent parabola focal length)• Off-axis angle or off-axis distance• Material• Necessary surface imperfection tolerance according to ISO 10110 (3/; 4/; 5/; etc.)• Coating146

Precision Optics
Optical Fabrication Methods

Free Form Surfaces
In general, free form surfaces do not exhibit any symmetries. They are always customer specific and can be defined by an equation. Additional specification of tabulated sagitta values is highly recommend. Free form surfaces are manufactured as single pieces. With respect tomachining, the production of an off-axis asphere from a single piece represents a free form as well. Table 3 shows LAYERTEC’s production
dimensions and tolerances for free form surfaces.
Table 3: Dimensions and tolerances of free form substrates

z

er

et

ng

i
en

op

iam

d

r
2

Ø/

α
te

tC

α

a

d

Dimension

ThicknessØ< 300 mm±0.2 mmw< 300 mm±0.1 mml< 450 mm±0.1 mm

α

< 45°

te

< 80 mm±0.1 mmd±0.1 mmSurface form tolerances (P-V)

λ/4(λ/10 on request)

Roughness< 0.3 nm

w

l

a
w
l

off-axis distancewidth
lengthteαdthickness
off-axis angle
distance between center beamand reference edge

Figure 15: Basic dimensional parameters of a free form substrate

Materials
The surface imperfection tolerance and the final tolerances strongly depend on the material of the substrate. LAYERTEC uses a processoptimized for Fused Silica. Materials like Zerodur®, ULE® or N-BK7® may be used in special cases.

Measurement
Measuring aspheric surfaces requires sophisticated devices. LAYERTEC applies 2 different measurement principles. See also page 152 ff.
• Single point interferometer:
Contactless measurement of the surface, measuring the surface point by point. Precision λ/4 on ≤ Ø 420 mm.
• Interferometer with reference surface:
The surface is compared to a known reference surface. Precision < 50 nm, on Ø ≤ 300 mm. Concave surfaces preferred.

147

Precision Optics
Optical Fabrication Methods

Special Surfaces
Particular applications in optics exhibit a demand for optical surfaces that are far away from flat, spherical or even aspheric surfaces. Thus,in the following such surfaces are referred to as special surfaces.
The fabrication of these special surfaces can typically not be addressed with conventional manufacturing technologies in optics. At
LAYERTEC a local correction technique with a footprint of ≈ 1 mm in diameter is used. This allows the fabrication of profiles with typicallateral features above 1 mm. In the set-up the handled substrates are up to 400 mm in diameter. Surface profiles are applied with a typicalfabrication error below 25 nm (along the z-axis). Furthermore, this technique allows a complete processing of the optical surface. In contrast to most local correction techniques there is no need for a safety margin around substrate edges.
Optical vortices are a well-known example of a special surface. They are mainly used in the generation of laser beams with a spiral phase.
The structure of an optical vortex is exemplary shown in figure 16a. With respect to the manufacturing of a vortex the main feature of sucha profile can be found in the edge, showing a typical height of several 100 nm. In the fabrication process the footprint of the local polishingtool smears out this edge. Figure 16b shows the surface form deviation of a real substrate (30 mm in diameter) processed by LAYERTEC.
b15.6

916.0614697.81

12552.31406.81261.3

10
8

Y range [nm]

6

115.8
-29.7
-174.25-317.87-461.484
2
0-2

Z range [nm]a-605.09-4-748.7-6-892.31-8-1107.73

-10
-12
-14
-15.6
-15.6 -14 -12 -10 -8 -6 -4 -2 0

2

4

6

8 10 12 14 15.6

X range [nm]Figure 16: Vortex substratea) Vortex side viewb) Surface form deviation of a real substrate14

169.3712141.4410

122.82
104.2
85.57

8
6

66.95
48.33
29.83
11.45
-6.93

Y range [nm]

4
2
0
-2

Z range [nm]Another application of special surfaces can be found in the compensation of thermal lenses. In this case the respective wavefront error
caused by a thermal lens is translated into a surface form deviation of a transmissive or reflective optical element. Such a surface is thenapplied to a real optics counteracting the thermal lens in the stationary working regime of the application. A typical example of the surface
form of such an element is shown in figure 17.

-25.31-4-43.69-6-62.07-8-89.64-10-12-14-14 -12 -10 -8 -6 -4 -2

0

2

4

6

8 10 12 14

X range [nm]Figure 17: Surface form profile of an optical element counteracting a thermal lens148

Precision Optics
Optical Fabrication Methods

Large Scale Optics
LAYERTEC offers large scale optics which are used for a variety of applications in industry (material processing, measurement, semiconductor industry, display production), science, medical and other areas. Processing technologies are offered for all common Fused Silica optics(special materials on request). LAYERTEC develops large optical components in cooperation with the customer from prototype to serial
production. LAYERTEC has suitable measurement equipment to ensure the promised specifications.

Figure 18: Quality control of large scale optics

Figure 19: Examples for large scale optics

Optical Components• Planar optics• Spheres• Cylinders• Aspheres, off-axis parabola• Free-form optics

Technologies for substrate fabrication• CNC grinding up to 2000 mm• Polishing (CNC and classical) up to 2000 mm• Interferometry (flat and cylindrical surfaces) up to2000 mm• Roughness measurement (tactile and optical) up to2000 mm• Multi-sensor coordinate measuring up to 2000 mm• Ultrasonic cleaning technology up to 1200 mm

Accuracy and quality of surfaces• Planarity up to λ/20
• Polishing level 4• Roughness Rq ≤ 0.5 nm• Surface defects down to 1 ppm of checking area

Optical Coating Technologies• IAD up to 1200 mm• Magnetron-sputtering up to 600 mm• Characterization of optical coatings (OPO-CRD, PCI, LIDT)

149

Precision Optics
Optical Fabrication Methods

Scanning Mirrors & Lightweight Structures

Figure 20: Scanning mirrors during CNC production

Figure 21: Examples for different types of scanning mirrors

Scanning mirrors are special deflection mirrors with an optical
function surface. By rotating the mirror, the direction of the reflected beam can be changed. With a single mirror, a line can bescanned. With a combination of 2 scanning mirrors, whose axes ofrotation are offset by 90 degrees, a two-dimensional surface canbe scanned.

scanning mirror (Y)laser source

Various CNC machining technologies are available for the production of scanner mirrors. Standard scanner mirrors are not yet lightweight components, but normal “solid” mirrors with “normal” dynamic requirements. However, these can be optimized according
to customer requirements in terms of weight (lightweight scanner
mirrors) or speed of movement (high-speed scanner mirrors).

scanning mirror (X)Figure 22: Working principle of the scanner mirror

Lightweight and high-speed scanner mirrors are characterized by herringbone-like structures, which are responsible for reducing the mass
moment of inertia by up to a factor of 4 (compared to “solid” material). The resonant frequency is increased by up to a factor of 1.5 bythis step, and the dynamic deformation is reduced by up to a factor of 1.5. These special shapes are used when a very fast change in the
direction of movement of the laser beam over the workpiece surface is desired.

radius of test area
total
thicknessdistance between mirror
and axis of gravity

axis of gravity
mirror side

Figure 23: Technical drawing of a scanner mirror

150

total width

axis ofgravitywidth of test area

total lenght
length of test area

bevel width 2

mounting
width

bevel width 1

mounting length

Figure 24: FEM simulation of mechanical deformation (blue = “stress-free”,
green = “stresses due to deformation”, red arrow = “torsional
direction”). The stresses in the component are homogeneously
distributed, there are no stress peaks. This ensures optimum
performance.

Precision Optics
Optical Fabrication Methods

Table 4: Specification of Lightweight Structures

Fused Silica

Standard

Limits for mirror sizes

small

large

small

large

small

large

Total width [mm]

20

80

40

80

15

40

Total length [mm]

20

80

40

80

15

40

Total thickness [mm]

3.2

6.35

6.35

9.5

2.5

6.35

Moment of inertia [g×mm²]

100

8000

120

2000

13

120

Resonance frequency in direction of rotation [Hz]

15000

3000

8000

4000

20000

8000

Max. Stress at 10 000 rad/s² [N/mm²]*

0.03

0.8

0.005

0.1

0.03

0.06

Form deviation at 10 000 rad/s² [nm]

100

450

50

300

5

50

*

Lightweight

High Speed

The angular acceleration of 10 000 rad/s² corresponds approximately to a frequency of 22 Hz when the amplitude is ±30°. This angular acceleration is an
example value to indicate stress and deformation. The stress and deformation in the substrate are assumed to be linear with respect to angular acceleration. Thus, doubling the angular acceleration will lead to a doubled amount of dynamic deformation.
Furthermore, the angular acceleration scales linearly with a change in the modulation amplitude and quadratically with respect to a change in frequency.

Coating is done by magnetron sputtering, IBS or evaporation and can be customized according to customer requirements.

Etalons & Waveplates
Etalons
As a kind of Fabry-Pérot interferometer, the etalon is typically made of a transparent plate with two reflective surfaces. Its transmittancespectrum, as a function of wavelength, exhibits peaks of high transmittance corresponding to resonances of the etalon. Etalons are widely used in telecommunication, lasers and spectroscopy for controlling and measuring the wavelength of laser sources. LAYERTEC offers
etalons of customized diameters and various materials depending on the wavelength range. Thicknesses down to 50 µm and a parallelism < 1 arcsec are possible subject to the diameter. Do not hesitate to contact us for the customized diameter and thickness you need.
Table 5: Specifications of etalonsThickness

Parallelism

Ø = 50 mm

Ø = 25 mm

Ø = 12.7 mm

Fused Silica≥ 200 µm

≥ 100 µm

≥ 50 µm< 1 arcsec

YAG≥ 200 µm

≥ 90 µm≥ 50 µm< 1 arcsec

CaF2

—

≥ 300 µm

≥ 100 µm

< 5 arcsec

Waveplates
LAYERTEC offers customer specific retardation plates made of crystalline quartz. Due to requirements for mechanical stability, there is aminimum feasible thickness depending on diameter. Thus, there is a constraint with respect to the shortest available wavelength for a given
waveplate order. For selected geometries LAYERTEC provides effective zero-order waveplates. These waveplates are made by combining
two individual waveplates with alignment of the fast axis of one plate to the slow axis of the other. The resulting net retardation of thisassembly is the difference between the two retardations. For two frequently requested diameters, examples are given below. Other diameters are available on request. Please contact us for further information.
Table 6: Specifications of waveplates made of crystalline quartzOrderØ = 25 mm

λ/2

Available wavelengths

Ø = 18 mm

Thickness Tolerance

Parallelism

K=0—

λ > 1530 nm±1 µm< 1 arcsec

K=1

λ > 720 nm

λ > 560 nm±1 µm< 1 arcsec

K=2

λ > 450 nm

λ > 350 nm±1 µm< 1 arcsec

λ/4

Available wavelengths

K=1

λ > 860 nm

λ > 660 nm±1 µm< 1 arcsec

K=2

λ > 500 nm

λ > 380 nm±1 µm< 1 arcsec

151

Precision Optics
Measurement Tools for Testing Substrates

Measurement Tools for Testing Substrates
Surface Form Deviations
Any machined substrate exhibits surface form deviations from its theoretical design. The effect of these deviations on the optical functionality of the optics can be categorized with respect to the spatial dimension of the deviations. The following section refers to deviations of
the optically active surface.
The inverse length of this spatial dimension – the spatial frequency – is used to mathematically describe the different kinds of deviations. A
rough classification of deviations distinguishes between Form (low spatial frequencies), Waviness (mid-spatial frequencies) and Roughness(high spatial frequencies).
Form deviations affect the wavefront of the passing light while leaving the direction of propagation nearly unchanged. They lead to a
distortion of the image or a significant alteration of the focal intensity distribution near the optical axis.
Waviness deviations also conserve the total energy of the propagating beam but mainly affect focal regions away from the optical axis. For
example, periodical deviations in this frequency band can give rise to the formation of parasitic secondary foci.
Finally, roughness affects the propagating wavefront on spatially small regions. These disturbances lead to an effective scattering of energy
off the direction of the main beam. Thus, there is a widespread intensity background resulting in a reduction of image contrast.
A quantitative distinction of form, waviness and roughness involves different optical and geometrical parameters, mainly the operating
wavelength as well as numerical aperture and focal length. Thus, the same surface form deviation may lead to a significantly different
optical behavior when used in different applications.

Surface Form Measurement
For the measurement of surface form deviation, LAYERTEC is equipped with laser interferometers and special interferometer set-ups
for plane, spherical, cylindrical, aspherical and parabolic surfaces. Additionally, a tactile measurement device (Taylor Hobson PGI 1240
Asphere®) is available for general aspheric and ground surfaces. Besides the purpose of quality control, surface form measurement is a key
function for the zonal polishing technology established at LAYERTEC.

Abbreviations• P-V: The peak-to-valley height difference• ROC: Radius of curvature of a spherically or cylindrically curved surface.
• λ: operating wavelength of the laser interferometer (e.g. 546 nm). The P-V value is stated in a fractional amount of λ. The actual
value of λ is stated in measurement reports.
For detailed information about the standards concerning specification of surface form deviation please see ISO 10110-5.

Accuracy of Interferometric Measurements

500
400
300
Y [mm] 200
100
0

0

100

200

300

400

50
0
Z [nm]-50
500

Without special calibration procedures, the accuracy of an interferometric measurement is only as accurate as the reference surface.
Calibration can increase the accuracy by a factor of 2 or more. Furthermore, the accuracy is influenced by the size of the measured
area and in case of a curved surface by the radius of curvature
itself. The accuracy values stated as “P-V better than …” in thefollowing articles are guaranteed values. Very often accuracies of
λ/20 or better will be achieved.

X [mm]

Figure 1: Height map of a flat surface with a diameter of Ø = 520 mm
polished and measured at LAYERTEC. The P-V value is λ/10
over the full aperture (Ø = 500 mm inspection area) after zonal
correction.

Standard Measurements
In general, the form tolerance of spherical and plane optics with diameters Ø ≤ 100 mm can be measured with an accuracy of P-V better
than λ/10 by using ZYGO® Fizeau interferometers. To cover a measurement range of ROC = ± 1200 mm over an aperture up to Ø = 100 mm,
LAYERTEC uses high precision Fizeau objectives. In many cases, a higher accuracy up to P-V = λ/30 is possible. Measurement reports canbe provided on request.

152

Precision Optics
Measurement Tools for Testing Substrates

Large Radius Test (LRT)
Surfaces with radii of curvature above ± 1200 mm are tested with a special Fizeau zoom lens set-up called Large Radius Test (LRT). This
set-up was developed by DIOPTIC GmbH in cooperation with LAYERTEC. Its operating range is ROC = ± 2000 … ± 20 000 mm at working
distances lower than 500 mm. The accuracy is guaranteed as P-V = λ/8 over Ø ≤ 100 mm, but typically it is better than P-V = λ/15. LRT has
the advantages that only one Fizeau-objective is needed to cover a wide range of radii of curvature and that the working distance is kept
small. This reduces the influence of disturbing air turbulences during the measurement.

Surface Roughness Measurement
In many applications, scattered light represents a crucial restriction to the proper operation of an optical device. On the one hand, scattered light reduces the intensity of the light propagating through the system, leading to optical losses. On the other hand, it also leads toa noise background of light reducing the overall contrast of imaging optics. The amount of scattered light produced by an optic is mainly
determined by its surface roughness. Thus, requirements to the surface roughness are often necessary to guarantee the proper operationof a device. For a quantitative comparison, the RMS roughness is a widely-used measure to specify optical surfaces. It is defined as the
root-mean-square of the surface height profile z:1

Rq =z²( x) dx ,

L

Sq =

1
A

z²( x, y) dx dyHere the letter ‘R’ indicates line scans according to ISO 4287 while the letter ‘S’ refers to the evaluation of a scan on a two-dimensional
measurement area as described in ISO 25178. The scan field size (maximum spatial frequency) as well as the resolution of the measurement set-up (minimum spatial frequency) affect the numerical value of Rq and Sq. For that reason, the specification of an RMS roughness
value requires the specification of the underlying band of spatial frequencies as well. Often, technical drawings are lacking information on
the frequency band and thus become meaningless. By using the power spectral density (PSD) of a surface, the distribution of the surface
roughness with respect to the spatial frequencies becomes obvious. The RMS value of a surface simply follows from integration of the PSD
over the given spatial frequency band. Generally, the scattered light of optical surfaces produced for the UV-NIR spectral range is dominatedby spatial frequencies ranging from 0.01 to 10 µm-1.
OPF (5x)

OPF (50x)

AFM (25 μm)

AFM (2.5 μm)

structural length

1 mm
10-26

100 μm

10 μm

1 μm

100 nm

10 nm

10-27
10-28
10-30

0.8

10-31

0.7

10-32

0.6

10-33

0.5

10-34

0.4

10-35

0.3

10-36

0.2

10-38

0.1

10-39
103

104

105

106

107

Sq [nm]PSD [m4]

10-29

At LAYERTEC, different phase shifting and phase-shift masking
optical surface profiler (Sensofar®, 4DTechnology®) and an atomic
force microscope (AFM) DI Nanoscope 3100® are used to cover
the given frequency band. The optical profilers cover low spatial
frequencies and have an acquisition time of a few seconds. It is
used for the general inspection of the polishing process and is able
to identify surface defects and inhomogeneities. The AFM addresses high spatial frequencies using scan field sizes of 2.5 × 2.5 µm²
and 25 × 25 µm² and has an aquisition time of 10 to 30 minutes.
Therefore, it is used primarily for the development of polishing processes. It further serves to monitor the LAYERTEC premium-polishing process and especially optics for UV applications with Sq <0.2 nm (spatial bandwidth: 7 – 1200 nm) with respect to quality
control. Measurement reports are available on request.

0108

spatial frequency [1/m]Figure 2: PSD of a LAYERTEC standard polish obtained by combining measurements using AFM and optical profiler (OPF). The right axis
shows Sq values on a logarithmic grid over spatial frequencies.
To obtain the total roughness Sqtot over multiple bars Sqi, squarevalues have to be added Sqtot2 = Sq12 + Sq22 + …

153

Precision Optics
Measurement Tools for Testing Substrates

Measurement Systems for Testing Substrates
Large Aperture Metrology
Especially for laser optics with large dimensions, LAYERTEC uses
a high performance Fizeau interferometer and a Twyman-Greeninterferometer within the following measurement ranges:• Plane surfaces: Ø ≤ 300 mm with an accuracy up to λ/20
(633 nm) and Ø ≤ 600 mm better than λ/10
• Spherical surfaces: Ø ≤ 600 mm with an accuracy better than
λ/10 (633 nm)• Parabolic surfaces: Ø ≤ 300 mm full aperture measurementwith an accuracy up to λ/10 (633 nm)

Figure 3: Interferometry of large surfaces

Contactless Metrology
The metrology system LuphoScan®, developed by Luphos GmbH,
allows an ultra-high precision measurement of distance and surface form. The unique system combines many advantages of other distance measurement systems without their disadvantages ofnecessary contact, small working distance or tiny working range.
This technology allows the determination of the topology of different objects down to the nanometer range.
Highly reflective objects as mirrors or metal coated substrates canbe measured as well as transparent objects providing only weakreflectance (glass lenses, substrates).

Figure 4: LuphoScan® metrology system

Due to its measurement range, it is possible to resolve structuresof up to 1 mm height with a precision of ± 5 nm. Especially, topological errors of aspheric surfaces can be exactly determined andused for a correction of the form parameters during the polishingprocess.

Tactile Surface Profiler
The Talysurf PGI 1240® is a tactile surface profile measuring tool
used to characterize strongly curved surfaces. A small tip is in contact with the surface and moves along a line while its vertical displacement is measured.
The measurement principle is independent of surface topology or
optical properties such as coatings or thin contaminations, which
often prevent direct interferometry. The vertical accuracy depends
on the gradient of the surface and can reach values of 500 nm,
which corresponds to ≈ λ (633 nm).
LAYERTEC uses this tool for measurements of small to mid-size
non-spherical surfaces up to a diameter of 200 mm.

Figure 5: Taylor Hobson Talysurf PGI 1240®

154

Precision Optics
Measurement Tools for Testing Substrates

84.8

Optical Profilometry

Y range: 170 μm

0

20

-84.8

40

-84.8

84.8
X range: 170 μm

Figure 6: Optical profiler Sensofar®

Figure 7: Surface defects visualized by the optical profiler

A 3D optical surface profiler (Sensofar®) based on a white light interferometer is used to visualize the surface form and roughness of our
substrates. The profiler is furthermore applied for the characterization of surface defects and other structures in the range of sizes from
0.5 μm up to 100 μm.

Atomic Force Microscopy
LAYERTEC utilizes an atomic force microscope (AFM) with a measurement range between 1 µm and 25 µm. It is used to control the
special polishing processes for surface roughness values below Sq ≤0.5 nm as well as to provide inspection reports on request.

Figure 8: DI Nanoscope 3100 AFM®

Defect Analysis
LAYERTEC has developed an automated measurement system forthe detection and analysis of defects and scratches on optical surfaces. This system enables LAYERTEC to classify defect sizes according to ISO 10110-7. Thus, quality control procedures, such as
final inspection, are facilitated, especially for high quality optics
with defects specified below 25 µm.

Figure 9: Defect inspection system for optical components

155

Optical Coatings

Optical Coatings

Chapter Index
Coating Technologies......................................................157
Thermal and E-Beam Evaporation.........................................157
Sputtering............................................................................158
Optical Interference Coatings..........................................160
Basics...................................................................................160
Antireflective Coatings (AR)..................................................161
Mirrors and Partial Reflectors................................................162
Dielectric Broadband Coatings..............................................162
Optical Losses......................................................................163
Stress...................................................................................163
Angle Shift...........................................................................164
Polarization Effects...............................................................164
Documentation of Coating Performance at LAYERTEC........165
Metallic Coatings............................................................166
Silver....................................................................................166
Gold.....................................................................................166
Aluminum............................................................................166
Chromium............................................................................166
Protective Layers..................................................................166
Metal-Dielectric Coatings................................................167
Measurement Tools for Optical Coatings.........................168
Spectral Photometry.............................................................168
Cavity Ring-Down Spectroscopy...........................................168
Laser-Induced Damage Threshold (LIDT)...............................172
Absorption Behavior.............................................................174
Defect Inspection System for Coatings.................................175

156

Optical Coatings
Coating Technologies

Coating Technologies
There are four basic processes that have been developed since about 1930. Besides layer deposition by dipping (sol-gel layers) and layer
deposition from the gas phase (atomic layer deposition), only two technologies currently dominate the industry:
1. Layer deposition by evaporation of the layer forming materials in vacuum
2. Layer deposition by sputtering (impact processes)
LAYERTEC strives to offer the most effective, cost-efficient coating method for the respective application in direct customer contact.

Thermal Evaporation

Ion Assisted Evaporation

Magnetron Sputtering

Ion Beam Sputtering

Particle energy
during deposition
Substrate temperature
required during deposition

300 °C

100 °C … 300 °C

20 °C

20 °C

Coating structure

Coating tension

Scattered light
Climatic andmechanical stability
Coatable surface area
(Chamber size)
Coating accuracy

Figure 1: Overview of the coating technologies possible at LAYERTEC

Thermal and E-Beam Evaporation
Working Principle
Thermal and electron beam evaporation are the most common techniques for the production of optical coatings. LAYERTEC uses thesetechniques mainly for UV coatings. The evaporation sources are mounted at the bottom of the evaporation chamber. They contain thecoating material which is heated by resistive heating (thermal evaporation) or by an electron gun (e-beam evaporation).
The method of heating depends on the material properties (e.g. the melting point) and the optical specifications. The substrates aremounted on a rotating substrate holder at the top of the evaporation chamber. Rotation of the substrates is necessary to ensure coatinghomogeneity. The substrates must be heated to a temperature of 150 – 400°C, depending on the substrate and coating materials. This
provides low absorption losses and good adhesion of the coating to the substrates.
Ion guns are used to get more compact layers. LAYERTEC is equipped with several evaporation machines covering the whole bandwidthof the above-mentioned techniques from simple thermal evaporation to ion assisted deposition (IAD) using the APS pro® and LION® ion
sources.
APS pro® and LION® are trademarks of Bühler Alzenau GmbH.

157

Optical Coatings
Coating Technologies

Properties of Evaporation Coatings

heating: 20 − 300°C

evaporat

io
n

be
a

ed particlmes

substrate

opt

The energy of the film forming particles is very low (≈ 1 eV). That is
why the mobility of the particles must be enhanced by heating thesubstrates. The packing density of standard evaporated coatings isrelatively low and the layers often contain micro-crystallites. This
results in relatively high scattering losses (some tenth of a percent
to some percent, depending on the wavelength). Moreover, atmospheric water vapor can diffuse in and out of the coating depending on temperature and humidity, resulting in a shift of the reflectance bands by ≈ 1.5 % of the wavelength. Shift-free, i.e. dense,
evaporated coatings can be produced by IAD using the APS pro®
and LION® ion sources which provide very high ion current densities. Nevertheless, evaporated coatings have also high laser damage thresholds and low absorption. They are widely used in lasers
and other optical devices.

iona
ion l
sou
rce

e-beam gun
or boatvacuumpump

Figure 2: Schematic drawing of an evaporation plant

Sputtering
Working Principle
In general, the term “sputtering” refers to the extraction of particles (atoms, ions or molecules) from a solid by ion bombardment. Ions areaccelerated towards a target and collide with the target atoms. The original ions as well as recoiled particles, move through the material,
collide with other atoms and so on. Most of the ions and recoiled atoms remain within the material, but a certain fraction of the recoiled
atoms is scattered towards the surface by this multiple collision process. These particles leave the target and may then move to the substrates and build up a thin film.

Properties of Sputtered Coatings
Because of the high kinetic energy (≈ 10 eV), i.e. high mobility of the film forming particles, sputtered layers exhibit:• An amorphous microstructure• A high packing density (which is close to that of bulk materials)
These structural characteristics result in very advantageous optical properties such as:• Low losses due to scattered light• High stability of the optical parameters under various environmental conditions due to the blocking of water diffusion• High laser-induced damage thresholds• High mechanical stability
LAYERTEC currently operates over 40 magnetron and IBS systems, so that the optimum deposition technology can be selected for eachcustomer application. The maximum substrate diameter for IBS sputtering is currently 30 cm, for magnetron sputtering 60 cm. The competitions of the SPIE Laser Damage conference of the last years show that each coating technology offers advantages for certain applications.
Suitable for your specifications, LAYERTEC’s coating engineers select the appropriate method.

158

Optical Coatings
Coating Technologies

Magnetron Sputtering

vacuumpump

substrate

sputtered atom from target

plasma(e.g. argon)
e−

anode

anode

argon

Ions are delivered by a gas discharge which burns in front of thetarget. It may be excited either by a direct voltage (DC-sputtering)or by an alternating voltage (RF-sputtering). In the case of DC-sputtering the target is a disk of a high purity metal (e.g. titanium).
Adding a reactive gas to the gas discharge (e.g. oxygen) resultsin the formation of the corresponding compounds (e.g. oxides).
For RF-sputtering, dielectric compounds (e.g. titanium dioxide) can
also be used as targets.
Developments at LAYERTEC have taken magnetron sputteringfrom a laboratory technique to a very efficient industrial process,which yields coatings with outstanding properties especially in the
VIS and NIR spectral range. The largest magnetron sputtering machine can coat substrates up to a diameter of 600 mm.

Ar+-Iontarget cathodecoolingmagnets

Figure 3: Schematic drawing of magnetron sputtering

Ion Beam Sputtering
This technique uses a separate ion source to generate the ions.
To avoid contaminations, RF-generators are used in modern IBS
machines. The reactive gas (oxygen) is in most cases provided by asecond ion source. This results in a better reactivity of the particles
and in more compact layers.

sub

str
ate

multipletargetcarousel

The main difference between magnetron sputtering and ion beam
sputtering is that ion generation, target and substrates are completely separated in the IBS process while they are very close toeach other in the magnetron sputter process.

depoion sitionb
sou eamrce

assistingion beamsourcevacuumpump

Figure 4: Schematic drawing of ion beam sputtering (IBS)

159

Optical Coatings
Optical Interference Coatings

Optical Interference Coatings
The purpose of optical coatings is to change the reflectance of optical surfaces. According to the materials used, metallic and dielectric
coatings can be distinguished. Metallic coatings are used for reflectors and neutral density filters. The achievable reflectance is given by
the properties of the metal. Common metals used for optical applications are described on page 166. Dielectric coatings use opticalinterference to change the reflectance of the coated surfaces. Another advantage is that the materials used in these coatings show very
low absorption. The reflectance of optical surfaces can be varied from approximately zero (antireflection coatings) to nearly 100 % (lowloss mirrors with R > 99.999 %) using optical interference coatings. These reflectance values are achieved only for a certain wavelength ora wavelength range.
The effect of optical coatings is based on three physical effects:
1. Reflection of light at refractive index boundaries
2. Interference of partial waves within the structure
3. Exploitation of phase shift of the reflected waves at refractive index boundaries
Such structures are possible if transparent layers with plane-parallel interfaces can be deposited with a thickness of less than approx. 1 µm.
Complex structures consist of alternating layers of several materials with specifically adjusted optical thickness.

Basics(c) (d)(a)incident
beam

reflected
beams

high index layer(b)substrate(e)(c) (d)(a)incident
beam

reflected
beams

(b)

low index layer

substrate(e)Figure 1: Schematic drawing to explain the interference effect of quarterwave layers of a high index material and a low index material

160

The influence of a single dielectric layer on the reflectance of asurface is schematically shown in figure 1. An incident beam (a)is split into a transmitted beam (b) and a reflected beam (c) at the
air-layer interface. The transmitted beam (b) is again split into a reflected beam (d) and a transmitted beam (e). The reflected beams(c) and (d) can interfere. In figure 1 the phase is represented by theshading of the reflected beams. The distance from “light-to-light”
or “dark-to-dark” is the wavelength. Depending on the phase difference between the reflected beams, constructive or destructive
interference may occur. The reflectance of the interface between
the two media depends on the refractive indices of the media, theangle of incidence and the polarization of the light.

Optical Coatings
Optical Interference Coatings

In general, it is described by the Fresnel equations:

Rs =

Rp =

n 1 cos α − n 2 cos β²
Rs … reflectance for s-polarization
Rp … reflectance for p-polarization
n1 … refractive index of medium 1n 1 cos α + n 2 cos β
n 2 cos α − n 1 cos β

n2 … refractive index of medium 2²

α … angle of incidence (AOI)
β … angle of refraction (AOR)n 2 cos α + n 1 cos β

For normal incidence (α = ß = 0°) the equations can be reduced to the simple expression:R =n2 − n1 ²
n2 + n1

The phase difference between the beams (c) and (d) (see figure 1) is given by the optical thickness n × t of the layer (the product of therefractive index n and the geometrical thickness t). Furthermore, a phase shift of π, i.e. one half-wave, has to be taken into account, if lightcoming from a low index medium is reflected at the interface to a high index medium. Please refer to the literature cited on page 167
for a detailed explanation of the physics of optical interference coatings. Below are a few rules to help customers understand the opticalproperties of the coatings described in this catalog:• High index layers increase the reflectance of the surface. The
maximum reflectance for a given wavelength λ is reached
for n × t = λ/4. Only in the case of an optical thickness n × t= λ/2, the reflectance of the surface does not change for thiswavelength λ.

• Low index layers decrease the reflectance of the surface. The
minimum reflectance for a given wavelength λ is reached forn × t = λ/4. Only in the case of an optical thickness n × t =λ/2, the reflectance of the surface does not change for thiswavelength λ.

Antireflective Coatings (AR)A single low index layer can be used as a simple AR coating. The most common material for this purpose is magnesium fluoride with arefractive index of n = 1.38 in the VIS and NIR. This material reduces the reflectance per surface to R ≈ 1.8 % for Fused Silica and nearlyzero for sapphire.
Single wavelength AR coatings consisting of 2 to 3 layers can be designed for all substrate materials to reduce the reflectance for the
given wavelength to nearly zero. These coatings are used especially in laser applications. AR coatings for several wavelengths or for broad
wavelength ranges are also possible and consist of 4 to 10 layers.
b
5

5

4

4

3

3

R [%]

R [%]

a

2

2

1

1

0
350

400

450

500

550

600

650

700

wavelength [nm]

750

800

0
350

400

450

500

550

600

650

700

750

800

wavelength [nm]Figure 2: Schematic reflectance spectra:a) Single wavelength AR coating (“V-coating”)b) Broadband AR coating

161

Optical Coatings
Optical Interference Coatings

Mirrors and Partial Reflectors
The most common mirror design is the so-called quarter-wave stack, i.e. a stack of alternating high and low index layers with equal optical
thickness of n×t = λ/4 for the desired wavelength. This arrangement results in constructive interference of the reflected beams arising at
each interface between the layers. The spectral width of the reflection band and the maximum reflectance for a given number of layer pairs
depend on the ratio of the refractive indices of the layer materials. A large refractive index ratio results in a broad reflection band while anarrow reflection band can be produced using materials with a low refractive index ratio.
TiO2 / SiO2

R [%]thickness [nm]substrate

air

100
90
80
70
60
50
40
30
20
10
0
500

600

700

800

900

Ta2O5 / SiO2

1000

1100

wavelength [nm]Figure 3: Schematic drawing of a quarter-wave stack consisting of layerswith equal optical thickness of a high index material (dark green)
and a low index material (light green)

Figure 4: Reflectance spectra of quarter-wave stacks consisting of 15 pairsof Ta2O5/SiO2 and TiO2/SiO2

To visualize the effect of different refractive index ratios, figure 4 compares the reflectance spectra of quarter-wave stacks consisting of
15 pairs of Ta2O5 + SiO2 (Δn ≈ 0.66) and TiO2/SiO2 (Δn ≈ 0.91) for 800 nm.
The theoretical reflectance will approach R = 100 % with an increasing number of layer pairs, assuming that ideal coatings have zeroabsorption and scattering losses. Partial reflectors with several discrete reflectance values between R = 0 % and R = 100 % can be manufactured using only a small number of layer pairs (see figure 5). Adding non-quarter-wave layers to a stack optimizes the reflectance toany desired value.

R [%]15 pairs
100
90
80
70
60
50
40
30
20
10
0

500

10 pairs

600

700

5 pairs

3 pairs

800

900

2 pairs

1000

1 pairFigure 5 also shows that an increasing number of layer pairs resultsin steeper edges of the reflectance band. This is especially important for edge filters, i.e. mirrors with low reflectance side bands.
Extremely steep edges require a large number of layer pairs which
also results in a very high reflectance (HR). Extremely high reflectance values require very low optical losses. This can be achievedby using sputtering techniques.

1100

wavelength [nm]Figure 5: Calculated reflectance of quarter-wave stacks consisting of 1, 2,
3, 5, 10 and 15 layer pairs of Ta2O5/SiO2 for 800 nm

Dielectric Broadband Coatings
The first step to broadband mirrors and output couplers is to use coating materials with a large refractive index ratio. The bandwidth canbe further increased by using special coating designs i.e. by using non-quarter-wave layers.
The easiest way is to combine two or more quarter-wave stacks with overlapping reflectance bands. However, this results in an increaseof optical losses at the wavelengths where the bands overlap. Moreover, multiple stack designs cannot be used for ultrafast lasers because
they induce pulse distortion.
LAYERTEC offers special all-dielectric broadband components for ultrafast lasers up to a bandwidth of one octave, i.e. 550 nm – 1100 nm(see page 49 f.)
An even larger bandwidth can be achieved using metals. However, the natural reflectance of metals is limited to 92 – 99 % (see page166), but it can be increased by dielectric coatings. For such ultra-broadband metal-dielectric mirrors see page 76 and 87 ff.

162

Optical Coatings
Optical Interference Coatings

Optical Losses
Light, which impinges on an optical component is either reflected, transmitted, absorbed or scattered. From this basic point of view, theenergy balance can be written in the simple equation
R + T + A + S = 1 (with R … Reflectance, T … Transmittance, A … Absorption and S … Scattering).
In laser physics and precision optics absorption and scattering are summarized as optical losses because the absorbed and scattered part ofthe incoming light can no longer be used as a carrier of information or as an optical tool. In practice, the reflectance which can be achieved
depends on the absorption and scattering losses of the optics.
Scattering losses increase drastically with decreasing wavelength, which can be described by the Mie theory (scattering by particles with diameters in the order of λ, S ~ 1/λ²) and Rayleigh theory (scattering by particles with diameters < λ, S ~ 1/λ4). Depending on the surface andbulk structure, Mie and Rayleigh scattering occur simultaneously. Scattering losses depend critically on the microstructure of the coatings
and as such on the coating technology used. Usually, coatings produced by evaporation techniques show significantly higher scattering
losses than coatings produced by magnetron sputtering or ion beam sputtering. The strong dependence of the scattering losses on the
wavelength is the reason why scattering losses are a huge problem in the UV range while they are less important in the NIR and beyond.
Absorption in optical coatings and substrates is mainly determined by the band structure of the materials. Common oxide materials show
band gaps of 3 to 7 eV which correspond to absorption edges in the NUV and DUV. Fluorides have band gaps of 9 to 10 eV resulting inabsorption edges in the VUV spectral range (for more information please see page 138 ff). Some materials also show absorption bands inaddition to the basic absorption edge as seen in the absorption band of Si-O-H bonds in Fused Silica around 2.7 µm. Defects in the layers
form absorbing states in the band gap of the materials. These defects may result from contaminations or from the formation of non-stoichiometric compounds. Optical coatings must be optimized with respect to low contamination levels and good stoichiometry. This kind ofabsorption losses also increases with decreasing wavelength.
The amount of all kinds of losses depends on the thickness of the layer system. Each layer pair increases the theoretical reflectance; however, in practice, it also increases the optical losses. There is an optimum number of layer pairs which generates the maximum reflectance,
especially for evaporated coatings with relatively large scattering losses.
Table 1: Reflectance of HR mirrors in different spectral regions (for AOI = 0°)

Wavelength Range

Materials

Coating Technology

Reflectance≈ 200 nmfluorides

evaporation> 98.0 %≈ 250 nmoxidesIAD
sputtering> 99.0 %> 99.7 %≈ 300 nmoxidesIAD
sputtering> 99.5 %> 99.9 %≈ 350 nmoxidesIAD
sputtering> 99.8 %> 99.95 %VISoxidesIAD
sputtering> 99.9 %> 99.95 %Low Loss Mirrors VISoxidessputtering> 99.99 %NIRoxidesIAD
sputtering> 99.9 %> 99.98 %Low Loss Mirrors NIR

oxidessputtering> 99.998 %StressAnother effect which limits the number of layers is the mechanical stress in the coating. This stress results from the structure of the layers
but also from different thermal expansion coefficients of substrate and coating. Mechanical stress may deform the substrate, but it may
also result in cracks in the coating or in a reduced adherence of the coating.
Stress can be limited by material selection and the optimization of process temperature, deposition rate and, in case of ion assisted andsputtering processes, ion energy and ion flux.

163

Optical Coatings
Optical Interference Coatings

Angle Shift
A special feature of interference coatings is the angle shift. It means that features shift to shorter wavelengths with increasing angle ofincidence. Turning an optical component from AOI = 0° to AOI = 45° results in a downshift of the features by about 10 %. The angle ofincidence must be known to design any optical coating. Moreover, polarization effects must be taken into account at non-normal incidence(see below).
Please note that the angle of incidence varies naturally if curved surfaces are used. Lenses in an optical system always have a range ofacceptance angles which is determined by the shape of the lens and by the convergence or divergence of the beam. If these features
are known, AR coatings can be improved significantly. Besides the shift, broadband AR coatings often show an increased reflectance at
AOI ≥ 30° (see figure 6a).
The angle shift offers the possibility of angle adjustment of an interference coating. This is especially useful in the case of filters and thinfilm polarizers. These optics show extremely narrow spectral ranges of optimum performance. It may decrease the output and increase
the costs drastically if the specifications for wavelength and AOI are fixed. Angle adjustment (see figure 6b) is the best way to optimize
performance and to minimize costs.
a

AOI = 0°AOI = 20°

AOI = 30°b53Tu [%]

Ru [%]

4

2
1
0
350

400

450

500

550

600

650

700

750

800

AOI = 0°
100
90
80
70
60
50
40
30
20
10
0

770

wavelength [nm]

780

790

AOI = 10°800

AOI = 20°

AOI = 15°

810

820

830

wavelength [nm]Figure 6: Change of optical properties at varying AOIa) Angle shift and change of reflectance of a broadband AR coating (unpolarized light)b) Angle tuning of a narrowband filter for 800 nm

Polarization Effects
Besides angle shift, polarization effects appear at non-normal incidence. For optical interference coatings, it is sufficient to calculate thereflection coefficients for s- and p-polarized light. The reflectance of unpolarized light is calculated as the average of Rs and Rp.
Rs

Rp

AOI = 45°

30
25

R [%]

20
15
10
ΘB

5
0

0

10

20

30

40

50

60

70

80

90

wavelength [nm]transmitted beams,p-polarization

ΘB

e
fac l
sur rmano

incident beams,p-polarizationreflected beams-polarization

ΘB

ΘB

Brewster's angle

Figure 7: Definition of the terms s-polarized light and p-polarized light andreflectance of an uncoated glass surface vs. angle of incidence
for s- and p-polarized light164

To explain the meaning of the terms s-polarization and p-polarization, a reference plane must be determined (see lower part offigure 7). This plane is defined by the incident beam and by the surface normal of the optic. “S-polarized light” is that part of the lightwhich oscillates perpendicularly to this reference plane (“s” comesfrom the German word “senkrecht” = perpendicular). “P-polarized
light” is the part which oscillates parallel to the reference plane.
Light waves with a plane of oscillation inclined to these directions,
are split into p-polarized and s-polarized parts.
The upper part of figure 7 shows the reflectance of a glass surface
vs. AOI for s- and p-polarized light. The reflectance for s-polarized light increases with increasing angle of incidence. The reflectance for p-polarized light decreases initially, with R reaching 0 %at Brewster’s angle and then increasing again as the angle of incidence extends beyond Brewster’s angle. In principle, the same
applies for dielectric mirrors. For AOI ≠ 0°, the reflectance for s-polarized light is higher and the reflection band is broader than for
p-polarized light.

Optical Coatings
Optical Interference Coatings

T [%]

Ts
100
90
80
70
60
50
40
30
20
10
0
860

880

900

920

Tp

940

Tu

960

AOI = 45°980

In case of edge filters, where one of the edges of the reflectanceband is used to separate wavelength regions of high reflectanceand high transmittance, non-normal incidence results in a separation of the edges for s- and p-polarized light as the polarizations
experience different angle shifts. Thus, for unpolarized light theedge is broadened considerably.

1000

wavelength [nm]Figure 8: Polarization splitting of an edge filter. Please note that the edgesof the reflectance bands are steep for s- as well as for p-polarization even at AOI = 45°, but they are located at different
wavelengths. As a result, the edge of the reflectance band for
unpolarized light is considerably broadened

Documentation of Coating Performance at LAYERTECLAYERTEC includes a data sheet of transmittance and/or reflectance for each delivered optical component. The standard procedure is tomeasure the transmittance of the optics at AOI = 0°. A mathematical refinement of the theoretical design to this measured spectrum iscarried out and the reflectance at the desired AOI is calculated from this fit. Sputtered optical coatings for the VIS and NIR exhibit extremely
low scattering and absorption losses (both in the order of some 10-5). This has been confirmed in direct measurements of scattering andabsorption as well as via highly accurate reflectance measurements (e.g. by Cavity Ring-Down spectroscopy). The reflectance of sputteredmirrors can be approximated by measuring the transmittance T and using the simple formula
R = 100 % – T
due to very small the optical losses. In a normal spectrophotometer, the transmittance can be measured with an accuracy of about 0.1 to
0.2 % (depending on the absolute value); whereas reflectance measurements in spectrophotometers mostly have errors of about 0.5 %.
Thus, determining the reflectance of sputtered coatings in the VIS and NIR via transmittance measurements is much more accurate thandirect reflectance measurements. Please note that this method can only be applied because the optical losses are very small (which isone of the advantages of sputtered coatings). The method is also used for evaporated coatings in the UV to NIR spectral range where
the optical losses are only about 10-3 and can be included into the reflectance calculation. In the DUV range, the coatings usually show
scattering losses in the order of 10-3 … 10-2, depending on the wavelength. That is why, for example, fluoride coatings for wavelengths
below 220 nm are delivered with direct reflectance measurements. Direct reflectance measurements are also necessary for low-loss mirrors. LAYERTEC has a Cavity Ring-Down set-up for spectrally resolved measurements in the wavelength range between 210 to 1800 nm.

Figure 9: Download measurement report form from the LAYERTEC website

The data sheets are available and can be downloaded from the LAYERTEC website. Figure 9 shows the download window for data sheets.
To avoid mistakes, registration is required for batch number and part number.
165

Optical Coatings
Metallic Coatings

Metallic Coatings

R [%]Metals are the most common materials for mirror fabrication. Polished metals, especially gold, copper and bronze, were used as mirrors
in the ancient world. In the middle-ages, mirrors with relatively constant reflectance in the visible spectral range were fabricated using tin
foils and mercury which were put on glass. The era of thin film metal coatings on glass began in the 19th century when Justus von Liebig
discovered that thin films of silver can be manufactured using silver nitrate and aldehyde. For applications in precision optics and laser
physics, mirrors are produced by using the evaporation or the sputtering technique.

100
90
80
70
60
50
40
30
20
10
0

Al

0.2

0.4

0.6 0.8

1

Ag

2

Au

4

6

Cr

8

10

wavelength [μm]Figure 1: Reflectance of several metals versus wavelength (taken fromMacleod [2])LAYERTEC uses magnetron sputtering for manufacturing metallic coatings with extremely low scattering losses. Transparent, i.e. very thin,metal coatings can be produced with high accuracy. For detailed information about metallic mirrors and neutral density filters please see
page 52 f. and 87 f. Figure 1 gives an overview about the reflectance of the most common metals. In the following, we give someadvice about the use of these metals and the role of protective coatings.

Silver• Highest reflectance in the VIS and NIR• LAYERTEC produces protective layers by magnetron sputtering. These layers with very high packing density make silver
mirrors as stable as mirrors of other metals (e.g. aluminum). In
normal atmosphere lifetimes of 10 years were demonstrated.

• The use of protective layers is mandatory. Unprotected silver
is chemically unstable and soft
• Please see separate data sheets on page 52 f. and 87 f.

Gold• Similar reflectance as silver in the NIR• Chemically stable, but soft
• Protective layers are necessary to allow cleaning of gold
mirrors• LAYERTEC recommends using protected silver mirrors insteadof protected gold. The sputtered protective layers overcome
the insufficiencies of silver. The broader wavelength range,
the slightly higher reflectance and the favorable price also
make silver the better option.
• See separate data sheet about gold mirrors on page 93 f.

Aluminum• Relatively high and constant reflectance in the VIS and NIR• A protective layer is recommended because aluminum is soft• Highest reflectance in the UV• Please see separate data sheet on page 90 f.

• Surface oxide layer absorbs in the deep UV

Chromium• Medium reflectance in the VIS and NIR (R ≈ 40 % – 80 %depending on the coating process)• Good adhesive layer for gold and other metals on glass substrates• Hard (can be used without protective layer)

Protective Layers• Enable cleaning of optics and improve chemical stability• Influence the reflectance of the metal• Even very thin sputtered layers can be used for chemical protection of the metal because of the high atomic density of thelayers. Such layers show minimal influence on the VIS and NIR
reflectance of the metal.
166• Mechanical protection to enable cleaning of optics can only
be achieved by relatively thick protective layer systems• Optimization of the protective layer system for the wavelength of interest is particularly necessary in the UV

Optical Coatings
Metal-Dielectric Coatings

Metal-Dielectric Coatings

Figure 1: Off-axis parabola coated with a metal-dielectric silver mirror

Figure 2: Scanning mirrors with customized shape coated with a metal-dielectric silver mirror

In general, all layer systems consisting of metals and dielectric materials can be called “metal-dielectric coatings”. The most common ones
are metal-dielectric filters consisting of transparent metal layers which are separated by a dielectric layer. These filters are characterized byextremely broad blocking ranges which result from reflectance and absorption of the metallic layers. The spectral position of the transmittance band is determined by the optical thickness of the dielectric spacer layer.
Moreover, metal-dielectric reflectors can be used for a variety of applications in optics and laser physics. Metals and metallic coatings show
an extremely broadband natural reflectance which is restricted to about 90 % in the UV spectral range (aluminum), 96 % in the VIS (silver)
and 99 % in the NIR (gold and silver). Most of the metals must be protected by dielectric coatings to overcome limitations of chemical(silver) or mechanical stability (aluminum, silver, gold). Almost all metallic mirrors are metal-dielectric coatings. The protective coatings
always influence the reflectance of the metals. Single dielectric layers of any thickness lower the reflectance in most parts of the spectrum.
Multilayer coatings on metals can increase the reflectance of the metallic coating. The bandwidth of enhanced reflectance can also be
optimized for extremely broad spectral ranges as can be seen in figure 3. For more examples please see page 52 f., 76 f. and 87 ff.
AOI = 0°b

AOI = 0°

100

100

96

96

92

92

R [%]

R [%]

a

88

88

84

84

80
300

400

500

600

700

800

900

80
300

400

wavelength [nm]cstandard

enhanced 1

enhanced 2

500

600

700

800

900

wavelength [nm]enhanced 3

AOI = 0°

100

R [%]

99
98
97
96
95
650

700

750

800

850

900

950

1000

1050 1100

wavelength [nm]Figure 3: Reflectance spectra of silver mirrors with different top coatingsa) Protected silver mirrorb) Metal-dielectric mirror Optimized for high reflectance in the
VIS for use in astronomical applicationsc) Different designs for enhanced reflectance around 850 nm(AOI = 0°) for use in fs lasers

Literature[1] P. W. Baumeister: “Optical coating technology”, SPIE press monograph, PM 137, Washington 2004
[2] H. A. Macleod: “Thin film optical filters”, A. Hilger, Bristol, 1986
[3] A. J. Thelen: “Design of optical interference coatings”, Mc Graw Hill, New York 1989
[4] N. Kaiser, H. K.Pulker (eds.): “Optical interference coatings”, Springer Verlag Berlin Heidelberg, 2003

167

Optical Coatings
Measurement Tools for Optical Coatings

Measurement Tools for Optical Coatings
Spectral PhotometryStandard spectrophotometric measurements in the wavelength range λ = 190 nm to 3200 nm are carried out with commercial spectrophotometers:• PERKIN ELMER Lambda 1050®

• PERKIN ELMER Lambda 19®

• PERKIN ELMER Lambda 950• ANALYTIK JENA specord 250 plus®.

®

• PERKIN ELMER Lambda 750®

For measurements beyond this wavelength range, LAYERTEC is equipped with an FTIR spectrometer (λ = 1 to 20 μm) and a VUV spectrophotometer (λ = 120 to 300 nm). Please note that the absolute accuracy of spectrophotometric measurement amounts to 0.2 to 0.4 %over the full scale measurement range R, T = 0 to 100 %. For measurements with higher precision, a self-constructed set-up in the limited
range T = 0.1 to 0.0001 % with an accuracy up to 0.2 ppm is available.
Measurement technologies
20000

wavelength [nm]3200

2600 nm ... 4400 nm

FTIRSpectrometer
1 µm ... 20 µm

1700
1000

Cavity ring-down
measurement
210 nm ... 1800 nm

SpectrophotometerStandard
190 nm ... 3200 nm
VUV 120 nm ... 300 nm

210
120
0.001

0.01

0.1

99

99.9

99.99

99.99999.9999

R, T [%]

Figure 1: Measurement technologies and their range for reflectance andtransmittance measurements at LAYERTEC

Cavity Ring-Down Spectroscopy
High reflectance and transmittance values in the order of R, T = 99.5 to 99.9999 % are determined by Cavity Ring-Down Time measurements. This method is an absolute measurement procedure with high accuracy, e.g. R = 99.995 % ± 0.001 %. LAYERTEC operates various
CRD systems which were developed in cooperation with research institutes and universities. A schematic representation of the CRD method
is shown in figure 2.
Measurement
R1 = 99.99... %R2 = 99.99... %intensity

Intensity [a.u.]

I0

laser
pulse

I1
I2

Iin

I3
time
L, cavity

1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0

0

Signal

50

100

150

200

time [μs]Figure 2: Schematic representation of the CRD method

168

Figure 3: Exemplary mono-exponential CRD-curve of a highly reflecting
mirror pair for 450 nm with R = 99.995 % measured using aresonator length L = 228 mm

Optical Coatings
Measurement Tools for Optical Coatings

Working Principle
A laser pulse is coupled into an optical cavity consisting of two highly reflecting mirrors. The intensity of the light is measured behind thecavity. At the beginning, the intensity increases during the pulse duration. Then it decreases exponentially with the time constant τ according to

I T = I 0 exp

−

t

(1)

τ

with:

τ =

L

(2)

c (1 − RM)

where c is the speed of light and L is the cavity length. RM is the geometric mean of the mirror reflectance and can be derived from themeasurement of the time constant by

RM =√ R 1R 2 = 1 −

L
cτ

(3)

The accuracy of the measurement depends on the accuracy of the time measurement and the measurement of the cavity length. Please
note that errors of beam adjustment will always lower the decay time and/or will cause multi-exponential Ring-Down curves. In case of asingle- exponential decay (figure 3), stochastic errors cannot result in overstated reflectance values. Compared to a reflectance measurement in a spectrophotometer, CRD has two main advantages:• It is applicable for very high reflectance and transmittance values when using an enhanced measurement set-up.
• It is impossible to get measurement values which exceed the real ones.
The reflectance of single mirrors can be derived from pairs of measurements of a triplet of mirrors with R1, R2 and R3 being the reflectancevalues of the mirrors 1, 2 and 3, respectively, and RM12, RM23 and RM13 being the measured geometric means of the reflectance for thepairs of mirrors with the corresponding numbers. Three measurements of mirror pairs provide:

RM 12 =

√ R 1R 2

RM 23 =

√ R 2R 3

RM 13 =

√ R 1R 3(4)

Solving this system of equations the mirror reflectance can be calculated by:

R1 =
R2 =
R3 =

RM 12 RM 13
RM 23
RM 23 RM 12
RM 13

(5)

RM 13 RM 23
RM 12

In practice, this method is often used to determine the reflectance of a set of reference mirrors. Knowing the reflectance of a reference
mirror, the reflectance of a specimen mirror can directly be derived using equation (3).

169

Optical Coatings
Measurement Tools for Optical Coatings

100.000

R [%]99.99899.99699.99499.99299.990
500

510

520

530

540

550

560

570

580

590

wavelength [nm]Figure 4: Spectrally resolved CRD measurement

Broadband Cavity Ring-Down set-up and Applications
LAYERTEC has used CRD for the qualification of low loss mirrors for some years. Initially, there was the limitation that only discrete wavelengths, either generated by solid state lasers or diode lasers, could be used. The increasing demands concerning the optical properties ofbroadband mirrors required a measurement system for a spectral range over several hundreds of nanometers with a very high accuracy formeasuring high reflectance values. So LAYERTEC developed a novel spectrally broadband Cavity Ring-Down time measurement system incooperation with the Leibniz-Institute of Photonic Technology (IPHT) Jena e.V. [1][1] S. Schippel, P. Schmitz, P. Zimmermann, T. Bachmann, R. Eschner, C. Hülsen, B. Rudolph und H. Heyer: “Optische Beschichtungen mit geringsten Verlusten im UV-VIS-NIR-Bereich”, Tagungsband Thüringer Grenz- und Oberflächentage und Thüringer Kolloquium “Dünne Schichten in der Optik”,
7.– 9. September 2010, Gera; S. 268 – 282
Measurement

AOI = 0°

100.0

R [%]

99.9
99.8
99.7
99.6
600

700

800

900

1000

1100

An optical parametric oscillator (OPO), pumped by the third harmonic of a Nd:YAG laser, is used as light source. The use of harmonic conversion extends the tuning range towards the UV region
and provides a measurement range from 210 to 1800 nm without
gaps. In this measurement set-up, photo multipliers and avalanche
diodes are used as detectors. The Ring-Down cavity can consist of
two or three cavity mirrors. A two mirror cavity is used for reflectance measurements at 0° angle of incidence (figure 5 shows anexample of such a measurement).

1200

wavelength [nm]Figure 5: Reflectance spectrum of a negative dispersive broadband mirror
for the wavelength region 650 – 1100 nm with R > 99.9 %. The
measurement was performed by using an optical cavity consisting of 2 identical mirrors.

In contrast, a three mirror cavity set-up is used for non-normal measurements with two mirrors mounted on precision rotary stages. This
set-up can be used for wavelength scans at a constant angle or for angle resolved measurements at a constant wavelength (see figure 6).
If the reflectance of two mirrors is known, the reflectance of the third mirror can be calculated. If the incidence of light is not perpendicular
to the sample, the linear polarization of the OPO output beam can be rotated to set up perpendicular (s-) or parallel (p-) polarized light withrespect to the sample over the entire spectral measurement range.
a

b

s-pol

p-pol

100.00

mirror 3

99.98

2Θ

R [%]

mirror 1

99.96
99.94

Θ
mirror 2(sample)

99.92
99.90

30

40

50

60

70

angle of incidence [°]Figure 6: A V-shaped CRD cavity is used for the measurement. To analyze the polarization dependency of the mirror reflectance exactly, the measurement was
performed at parallel (p-pol.) and perpendicular (s-pol.) polarization with respect to the sample (mirror 2).
a) Schematic representation of a three mirror cavity (“V-cavity”)b) CRD reflectance measurement of a turning mirror for 1064 nm with variable angle of incidence, but with fixed wavelength of 1064 nm.

170

Optical Coatings
Measurement Tools for Optical Coatings

A standard cavity is used for the measurement of very high transmission values T > 99.5 % and of optical losses of components or gasesin the cavity. For transmittance measurements the sample is placed between the cavity mirrors. As the sample is an additional optical loss
for the cavity, the transmittance value can be calculated if the reflectance of the cavity mirrors is known. For measurements at a definedangle of incidence, the sample can be tilted in the range of 0° – 75° with respect to the optical axis of the cavity (figure 6b). Wavelength
resolved measurements as well as angle resolved measurements are possible. The latter is very useful for the determination of the optimum
angle for thin film polarizers (TFPs).
Rs

Tp

100.0
mirror 1

mirror 2

R,T [%]

99.6

Θsample

99.2
98.8
98.4
98.0

385

387

389

391

393

395

wavelength [nm]Figure 7: Schematic representation of a cavity for transmittance measurement

Figure 8: CRD measurement of a thin film polarizer for 390 nm: red curve– Rs (V-cavity), blue curve – Tp (two mirror cavity)

The same principle is used to determine optical losses of gases. First a spectrum of the evacuated cavity is measured. Then the cavity isfilled with gas and the ring-down spectrum is measured again. The optical loss is calculated according to formula 6. As an example figure
9 shows the optical loss spectrum of ambient air.

1

c

τ1

−

V = Optical loss between the cavity mirrors
c = Speed of light
L = Cavity lengthτ 0 = Decay time of evacuated cavity
τ 1 = Decay time of cavity with sample between R1 and R2

1
τ0

(6)

1.0

0.10

0.9

0.09

0.8

0.08

0.7

0.07

0.6

0.06

0.5

Rayleighscattering

0.05

H2O
0.4

H2O

H2O

0.04

O2

0.3
0.2

0.03

O2

0.02

O2

0.1
0.0
200

Optical losses after 1m [%]Attenuation coefficient α [10−³ × m−¹]

V =

L

300

400

500

600

700

H2O
0.01

800

900

1000

1100

1200

1300

1400

1500

0
1600

wavelength [nm]Figure 9: Measured optical loss spectrum of ambient air obtained with the LAYERTEC CRD set-up. For this measurement a total of 18 different pairs of CRD low
loss mirrors were used

Measurement reports can be provided on request. The broadband set-up permanently undergoes further development. The measurement
capabilities and the performance increase steadily.

171

Optical Coatings
Measurement Tools for Optical Coatings

Laser-Induced Damage Threshold (LIDT)LAYERTEC optics must be able to withstand extreme laser energies in some cases. In order to estimate the risk of possible damage to thecoatings, the laser-induced damage threshold (LIDT) is determined.
Damage in optics for the continuous wave or short pulse regime (ns-range) is mainly related to thermal effects such as increased absorption– either due to the intrinsic absorption of the coating materials or absorption by defects – or poor thermal conductivity and low melting
temperatures of the coatings. High power coatings require control of the intrinsic properties of the coating materials and the reductionof defects in the layers. Laser damage to picosecond and femto-second laser optics is mainly caused by field strength effects. Thus, highpower coatings for these lasers require materials with large band gap and very special coating designs.
The determination of the laser-induced damage threshold (LIDT), according to the standards ISO 11254-1 (cw and 1-on-1, i.e. single pulse
LIDT), ISO 11254-2 (S-on-1, i.e. multiple pulse LIDT) and ISO 11254-3 (LIDT for a certain number of pulses) requires laser systems operating under very stable conditions, precise beam diagnostics as well as online and offline damage detection systems. This is why a limited
number of measurement systems with only a few types of lasers is available (e.g. for 1064 nm at Laser Zentrum Hannover). For some of
the most prominent laser wavelengths, for example Argon ion lasers (488 nm or 514 nm), there is no measurement system available andcertified LIDT data cannot be provided.
The 1-on-1 LIDT (i.e. 1 pulse on 1 site of the sample) is not representative for the normal operation conditions. However, these values canbe used for comparing different coatings and for optimization procedures. The 1-on-1 values are directly related to the more practical S-on1 LIDT (LIDT for a given number “S” of pulses on the same site of the sample). They can be interpreted as the upper limit of the LIDT. Laser
systems with high repetition rates (some kHz) require lifetime tests expressed by LIDT values for high numbers of pulses.

LIDT Measurement Set-up at LAYERTEC
spatial beam profile
measurement

motorized positioning
along x-, y- and z-axis.
angle of incidence 0° – 60°

CDD

O

bj

.

CD

D

online damage
detected system

λ/2

BBO polarizer
energy meter and temporalbeam profile measurement
Nd:YAG laser - 1064 / 532 / 355 / 266 nm
10 Hz, 4 - 10 ns, 800 mJ @ 1064 nm

Figure 10: Nanosecond Nd:YAG laser LIDT measurement set-up at LAYERTEC.

Damage Probability

threshold
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0

0

measured data

Fit (ISO 21254-2)

5

10

15

20

reduced data

25

30

Fluence [J/cm2]

Figure 11: Damage probability of an antireflection coating for 355 nm
after 1000 pulses (pulse duration 7 ns, 10 Hz repetition rate)according to ISO 11254-2. This measurement was performed at
LAYERTEC.

172

LAYERTEC has developed its own LIDT measurement set-up for
in-house measurements with the aim to optimize the coatings concerning their stability against laser damage. The light source is a
Q-switched Nd:YAG laser which can emit wavelengths of 1064,
532, 355 and 266 nm. The pulse duration is about 4 to 10 ns
and the repetition rate is 10 Hz at all four possible wavelengths.
A close-to-Gaussian shaped beam profile is generated by focusing the laser beam with a lens. The spot size is in the region of
200 to 1000 μm (1/e² radius). The actual value depends on the
wavelength and the focal length of the lens. The set-up satisfies
the requirements of ISO 11254. It has an online detection system
based on a digital camera with fast image processing to inspect
the sample for damage after every laser pulse. Online beam profile measurements and the determination of the energy density
are done with a CCD camera beam profiler in combination withcalibrated energy measuring heads with single pulse resolution.
A motorized 3-axis stage and a sample holder for multiple pieces allow automated measurements at angles of incidence in therange of 0° to 60° either on reflecting or transmitting samples.
The linear polarization of the laser beam can be oriented for either
p- or s-polarization with the help of wave plates and a broadband
polarizer for the desired wavelength. The measurement set-up is
shown schematically in figure 10.
LAYERTEC tests samples by using its own procedure (please see
next section), because the ISO standards deliver unreliable values
for damage thresholds above 30 J/cm². However, if a measurement according to ISO 11254-2 is explicitly requested, the ISO procedure will be used. In this case, 100 or 1000 pulses will be used
at each measurement position in order to minimize measurement
time. This is not a test for longtime stability. However, LIDT resultsfor 100 or 1000 pulses are more realistic in comparison to 1-on-1
LIDT results. Figure 11 shows the result of a damage probability
measurement according to ISO 11254-2.
The in-house LIDT measurements are mainly intended to compare
LAYERTEC coatings among themselves for the purpose of coating and technology development. LAYERTEC provides LIDT results
on request, but please note that these results are only valid forthe specific measurement conditions (pulse duration, wavelength,
number of pulses, beam shape, repetition rate).

Optical Coatings
Measurement Tools for Optical Coatings

LAYERTEC LIDT Testing Procedure for Pulsed Laser Sources

Figure 12: Sample stage of the LIDT measurement set-up

Figure 13: LIDT beamline

LAYERTEC has gained a lot of experience in laser damage testing by utilizing the LIDT testing procedures according to ISO 11254. However, it became clear that the measurements are both cost and time intensive but often deliver only questionable results. Significantly lower
damage thresholds and strongly skewed damage probability distributions were observed in many cases. Troubleshooting the measurement
set-up did not reveal any issues leaving only other reasons to explain the measurement errors.
As mentioned above, LAYERTEC uses a relatively large Gaussian-shaped laser spot to measure the damage threshold. The typical spot size
is about 1 mm (1/e² diameter). Large spot sizes require a high laser energy and peak power to reach the fluence necessary to cause destruction at the testing site. Coatings with damage thresholds above 50 J/cm² require several hundreds of milli-joules laser pulse energy toshow damage. In this case, large amounts of debris are generated and deposited within a circle of several millimeters in diameter aroundthe damaged position. If an adjacent test site is located within this zone its damage threshold is significantly reduced due to the debris.
This systematic error can be avoided by choosing a larger separation between the measurement positions while providing enough test sites.
Very high damage thresholds above 100 J/cm² require a separation between adjacent positions of more than 10 mm.
The ISO standard assumes a symmetric distribution for the damage probability. LAYERTEC observes this behavior only at average damage
thresholds below 30 J/cm². Threshold probability distributions with average damage values above 30 J/cm² are significantly skewed towards lower values. Assuming that the influence of debris can be neglected, the main reason for this phenomenon are imperfections in
the coating and sometimes the surface quality itself. Contrary to ISO standards, significantly low threshold values should not be treatedas statistical outliers. Strictly speaking, they have to be taken into account. Otherwise, damage threshold measurements would provide
wrong values.
As discussed above, LIDT tests based on ISO standards are not viable for coatings with high damage thresholds. LAYERTEC developed
an LIDT measurement method, which is well suited to measure the minimal damage threshold of optical coatings for high power or highenergy laser applications. This procedure requires 4 to 7 testing positions with a separation of approximately 10 mm to each other on thesample. Wherever applicable, four identical samples with 25 mm in diameter are used to get 16 to 28 measuring positions per testingprocedure. Every position is irradiated with stepwise increasing energy densities. The energy range of the test laser is subdivided into 50
levels. For the most part, 100 laser pulses are applied at each energy level to watch for cumulative effects in the coating. The starting energy has to be low enough to prevent any laser-induced damage. Then, the energy is increased until laser-induced damage occurs at thetesting position.
All positions on the sample are irradiated in this way, until each position exhibits damage. For the purpose of measurement analysis, thehighest, the average and the lowest measured damage threshold are reported. Further statistical analysis is not carried out. All damage
threshold values measured by LAYERTEC, which are stated in this catalog, were determined according to the LAYERTEC LIDT testing procedure for pulsed laser sources. Additional measurements were performed by several partners, e.g. Laser Zentrum Hannover, Laser Labor
Göttingen and Friedrich Schiller University Jena.
Due to the limited number of measurement facilities and the need for lifetime tests in practical applications, it is also necessary to include
the measurements and lifetime tests (cumulative irradiation tests) of several customers into this catalog. Please take into account that thesevalues cannot be compared with a standardized LIDT measurement because the laser parameters given are those without damage. Besides,
these values always come with a measurement error, especially with respect to the determination of the spot size. Errors in the order ofabout 30 % must be taken into account. Information about parameters for long-time operation will certainly convince the customer to use
LAYERTEC optics. Sometimes, however, these tests will be required in the customer’s laser system. LAYERTEC supports such tests at thecustomer’s facility with a considerable discount for test samples.

173

Optical Coatings
Measurement Tools for Optical Coatings

Absorption Behavior
Photo-thermal Common Path Interferometry (PCI)

detector

HR coatingprobe beampump beam

distorted beam(wavefront)
due to thermallens effectFigure 14: Schematic drawing of a photo-thermal common path interferometer (PCI)

A photo-thermal common path interferometer (PCI) allows
LAYERTEC to determine the absorption of optical thin films andbulk materials. In this set-up, an optical surface is irradiated bya pump laser, resulting in the absorption of part of the infallingradiation, see figure 14. Due to thermal conduction, the absorbed
energy is dispersed as heat within the optics, leading to the formation of a thermal lens.
A second laser, the probe beam, irradiates the thermal lens which
deforms the wavefront of said probe beam. This deformation leads
to interference effects within the probe beam and can be measured as intensity variations with a photodetector. The magnitudeof the wavefront deformation is proportional to the amount ofenergy absorbed by the optics. The pump beam is switched on andoff periodically, with a modulation frequency of several 100 Hz.
Thus, the intensity of the probe interference-pattern is temporally
modulated as well.

Pump beams at 355 nm, 532 nm or 1030 nm are available for s- and p-polarized light, measurement may be conducted for angles ofincidence between 10° and 70°. However, a transmittance above 1 % for the wavelength of the probe beam, 635 nm, is required. Apartfrom that, any HR, PR or AR coating (including single layers) on most common substrates may be measured. Substrates have to be planewith a thickness of 1 – 12 mm. Calibration reports are available on request.

Intra Cavity Heating Measurement (for coatings)

laser discfolding mirror

pyrometer
HR coating
output coupler

Absorption losses in optical coatings result in heating of coating
and substrate. For average laser power levels above several kilowatts (cw), even low absorption losses in the range of some parts
per million cause significant heating of the optical component. For
example, the irradiated zone (1.5 mm in diameter) of an HR-coating with an absorption loss of 5 ppm at 1030 nm is heated to atemperature of about 80°C when exposed to a power of 80 kW.

power
meter

Figure 15: Intra cavity heating measurement set-up for HR-mirrors at
1030 nmLAYERTEC has built a heating measurement set-up for the purpose of quality assurance and technology development on high power optical components at a wavelength of 1030 nm. An Yb:YAG thin disc laser is used to generate a high power laser beam (figure 15). The set-up
consists of a laser disc, a pump chamber, a sample (e.g. a highly reflective mirror) which works as a folding mirror, a second folding mirror,
an output coupler, a laser power meter and a pyrometer for the temperature measurement. The beam spot size on the irradiated sample
surface area is 1.5 mm (1/e²) in diameter. A very high intra cavity laser power of about 120 kW (cw) is achieved by choosing an output
coupler with a relatively low transmittance value. Under these conditions, the power density on the sample is approximately 15 MW/cm².
Generally, coatings with a set-up-specific operating temperature lower than 100°C can be used for high power applications. Please notethat the average temperature of the optical component measured is clearly lower than the temperature within the small irradiated zone
on the coating.
For the purpose of achieving absolute absorption measurements, it is possible to calibrate the set-up with a set of samples with well-known
absorption. The absorption measurement of the calibration samples was performed by using the LID (laser-induced deflection) measurement set-up at the Leibniz-Institute of Photonic Technology (IPHT) Jena e.V..

174

Optical Coatings
Measurement Tools for Optical Coatings

Defect Inspection System for Coatings

Figure 16: Laser mirrors are placed in a special magazine holder for automated defect inspection at LAYERTEC.

Figure 17: Simplified inspection report of a laser mirror. The report shows
the sizes and the coordinates of large defects on the coatedsurface. Furthermore, all defects which were found are shown ina histogram plot.

LAYERTEC built a measurement system capable of counting and classifying defects in optical coatings and on uncoated optical surfaces.
The system detects down to 6 μm in size. It is able to inspect the complete surface of small as well as large optical components. DiametersØ ≤ 600 mm and surface slopes up to 25° can be analyzed. Small to medium-sized pieces are placed in a special sample holder magazine
which enables the automated measurement of a large number of pieces in a single inspection run (figure 16).
Measuring small defects is very challenging because the necessary microscope lenses have a very short depth of focus and require precise
adjustment and positioning. Another important factor is proper lighting. Finally, the wide range of available geometries demands a very
flexible control software, quickly adapting to new geometries in order to avoid collisions between the sample and the test system.
LAYERTEC constantly improves the system, enabling it to inspect cylindrical and aspherical optics while reducing effort and measurement
time. Defects are classified by size according to ISO 10110-7 and their position on the optical surface is recorded. Thus, the complete set of
microscopic imperfections on the optical surface can be visualized in a macroscopic defect map. Individual measurement reports, including
defect maps and defect distributions, can be generated on request. An exemplary inspection report is shown in figure 17.

175Specials

Specials

Chapter Index
Solderable Coatings........................................................177
Lithography.....................................................................178
Optical Assemblies..........................................................179
Laser Engraving...............................................................181

176

Specials
Solderable Coatings

Solderable CoatingsabcFigure 1: Examples for solderable optics

In the past years LAYERTEC has developed technologies to deposit solderable coatings, e.g. on the side edges, for custom parts as well as
series components. Please note that due to the necessary masking of the optical functional surfaces, the simplest possible geometries andcorrespondingly large transition areas between metal and dielectric coating should be selected.
Such coatings are the prerequisite for bonding glass and metals, e.g. for mechanical support or targeted cooling.

177

Specials
Lithography

Lithography
For special applications, it is necessary to coat only a partial area ofan optical component or to combine different coating systems on
the same surface. Essentially, all coating systems can be segmented. A large number of combination options is available (dielectric,
metallic). The simplest option is coating with a mechanical mask/
aperture, leaving the covered area of the surface uncoated.
However, the limits of this method are quickly reached for verysmall and geometrically complex structures. Since this method results in shielding effects in the covered area, structuring by meansof photo lithography can be a useful alternative. For this purpose,a light-sensitive resist is exposed to UV-light on the component
surface through a mask (to be prepared in advance). Dependingon the type of photo resist, the exposed or unexposed area is thenremoved in a chemical process (positive/negative resist). Now thepatterned plate is coated with the respective layer system over theentire surface, whereby the coating only has contact with the substrate in the defined area. Then the remaining photo resist with thecoating on it is removed (lift-off process).

Figure 1: Lithographically structured coating

The etching process offers another possibility for structuring. In this process, the structure is etched out of the fully coated surface using
appropriate etching solutions. This variant is particularly suitable for structuring metallic layers (Cr, Al, …).

Application Areas
Segmented components can be used for lateral phase and/or amplitude modulation and are therefore suitable for example for mode
selection or beam splitting. The structured components are designed for use in high power laser systems, the edges of the structures arelaser-resistant up to the kW range.

Production Possibilities
Fused Silica up to a size of currently 8 inches (plane) is used as the standard substrate material. On request, other materials are possible.
Dielectric or metallic layers can be combined and applied in segments according to customer requirements. Depending on the layer design,
structure sizes down to the micrometer range are possible.

Working Principle
Table 1: Possible lithography procedures

Procedure

EtchingLift-Off(PictureCoating material

Lift-Off

Chromium, gold, aluminum, copper

optional

dielectric, metallic, etc.

Structure size

> 5 µm, depending on the material and layer thickness

Structure height< 10 µm, depending on the material and structure size

Substrate

Fused Silica, 50 – 200 mm in diameter

Geometry

any, free cutting

Final geometry
Thickness

Additional Options• Multiple processing• Lithography on both sides• Ultrasonic Drilling• Cut to size on wafer saw
178

Etching)

25 – 200 mm
down to 5 mm
Ø > 10 mm
5 × 5 mm rectangular

Second Lift-Off

Specials
Optical Assemblies

Optical Assemblies
a

b

c

d

Figure 1: Examples for optical assembliesa) Laser welded beam splitterb) Polarizing beam splitting prismc) Custom laser welded assemblyd) Mounted hollow retro-reflector mirror

Optical assemblies provide complex functionality and performances, that might not be possible to achieve by single components. The
integration of multiple components into higher-level assemblies unlocks features and special properties unable to achieve by monolithic
elements, e.g. a broader spectral range of polarizing beam splitters or the integration of both mechanical and optical features.
LAYERTEC’s in-house capabilities include the handling, positioning, alignment, and mounting of optical and opto-mechanical components, as well as multiple joining techniques to meet challenging customer demands. These joining techniques range from cost-effective
and flexible to use adhesive bonding to organic-free optical contacting and bonding techniques suitable for high power and UV use. Our
special bonding process as well as an ultrafast laser micro welding process are best suited for high precision assemblies with demandingalignment tolerances. They provide very high mechanical strength and long term stability even under challenging environmental conditions.
Since both techniques result in intermediate layer free bonds they provide the lowest possible absorption and a high laser-induced damage
threshold.
Building on long-lasting expertise, LAYERTEC can support the development and engineering of customer specific solutions from component and coating to the optical assembly. Our engineering support includes help in component design and substrate fabrication techniques,coating and material selection and the application of appropriate mounting and joining technologies according to your application requirements. LAYERTEC furthermore provides functional testing and optical metrology as well as mechanical and environmental testing toensure performance specifications.
All the optics shown represent just a few manufacturing possibilities that have already been successfully realized. LAYERTEC’s strength lies
in finding individual solutions for complex problems.

179

Specials
Optical Assemblies

Custom Optics / Optical Assemblies• Retro-reflecting hollow roof mirrors / hollow retro-reflectors• Optical Cavities• Effective zero-order waveplates• Customized mounted and unmounted laser optic assemblies• Beam Splitters

Typical Specifications• Dimensions 0.5”…2” (others on request)• Surface form tolerance: λ/4 (others on request)• Clear aperture > 90 %• Angular Accuracy: 5 arcsec (higher accuracy on request)• Surface imperfection tolerance: 5/ 1 x 0.016 L1 x 0.004• Lateral Accuracy: 10 µm (depending on geometry)

Materials• Fused Silica• Various optical glasses and crystals• ULE®

• Metal mounts and holders• Crystalline Quartz
Most of LAYERTEC’s specialized coatings can be applied to individual components prior to joining or to the optical assembly after joining.
Please contact us to select appropriate coatings to satisfy your needs.

Capabilities and Expertise• Customized equipment for handling, adjustment, mounting,and joining• CNC machining of opto-mechanical components• Optical Alignment capabilities• Mechanical and environmental testing• Functional testing and optical metrology• Support in engineering and production of prototypes tovolume series

Joining Technologies• Adhesive bonding• Bonding of surface-activated polished surfaces• Optical contacting of highly planar glass surfaces• Ultrafast laser micro welding

Benefits• High thermal, mechanical, and long-term stability• Robust against thermal and environmental loads• Organic-free bonds with ultra-low absorption• High damage threshold, suitable for high power and UV use• Suitable for vacuum use, fluidic/hermetical sealing• Low wave front distortion• High adjustment accuracy

180

Specials
Laser Engraving

Laser Engraving
ab

Figure 1: Examples for laser engravings

LAYERTEC uses laser engraving as a standard for all substrates and optics made of Fused Silica. It is possible to mark the edge as well ascoated or uncoated functional surfaces.
The minimum character height is approximately 1.5 mm. The maximum substrate height when inserted is about 80 mm (including holder).
Usually the optics are engraved lying on the side. The maximum lateral extension is 190 mm (with restrictions on height and location ofengraving, see table below).
In direct contact with our sales department, please clarify for which materials and geometries such engraving is useful or necessary.
Table 1: Minimum requirements for laser engraving

Arrow Mark “^”“^” and Batch Numberø = 6 mm“^”, Batch Number and Material Number/ROC

ø = 10 mm

ø = 10 mm
t = 2 mmV

Engraving with a character (e.g. “^”):• t ≥ 2.0 mm• Ø ≥ 6.0 mm

l = 3 mm

B atch Numb e r

t = 2 mmEngraving with a character and batch number:• t ≥ 2.0 mm• Ø ≥ 10.0 mm

V

w = 3 mmEngraving with a character (e.g. “^”):• t ≥ 2.0 mm• l ≥ 3.0 mm

Batch Number

Part Numbe r

t = 5 mmEngraving with a character, batch number andmaterial number or ROC:
• t ≥ 5.0 mm• Ø ≥ 10.0 mm

l = 7 mml = 7 mm
t = 2 mm

B atch Numb e r

t = 2 mm
w = 3 mmEngraving with a character and batch number:• t ≥ 2.0 mm• l ≥ 7.0 mm

Batch Number
Part Numbert = 5 mm
w = 3 mmEngraving with a character, batch number andmaterial number:• t ≥ 5.0 mm• l ≥ 7.0 mm

181

Knowhow

Knowhow

Chapter Index
Polarization.....................................................................183
Dielectric Mirrors – Non-Normal Incidence......................184
Weakly Curved Substrates...............................................185
Surface Form Tolerances .................................................186
Surface Imperfection Tolerances.....................................187
Laser-Induced Damage Threshold (LIDT).........................188
Group Delay Distortion (GD & GDD)................................189
How to Mount Optics......................................................190
Cleaning of Optical Surfaces...........................................191

182

Knowhow
Polarization

Polarization
Reflection on a Plane Surface

Superposition of s- and p-Polarized Light

The plane of incidence (POI) is defined by the incident beamand the surface normal.

Any polarization state can be understood as a superposition ofs- and p-polarized light.

ce (POI)
inciden

sub

f
ne o
pla

ce
n

or
m
al

am

tra

refl

ec
te

db

Linearly Polarized Lights- and p-polarized light without phase shift results in linearlypolarized light.

s-pol. light

ea
m

su

rfa

t be
den
inci

ate
str

eam
ed b

itt
nsm

s - Polarization
Electric field polarized perpendicular (»senkrecht«) to the POI,
also known as σ - or TE (transverse-electric) polarization.

+ p-pol. light(in phase)= linearlypolarized
light

p -Polarization
Electric field polarized parallel to the POI, also known as π - or
TM (transverse-magnetic) polarization.
Circularly Polarized Lights- and p-polarized light with a phase shift of 90° results incircularly polarized light.
s-pol. light+ p-pol. light(out of phaseby 90°)= circularely
polarized
light

183

KnowhowDielectric Mirrors – Non-Normal Incidence

Dielectric Mirrors – Non-Normal IncidenceCenter Wavelength (CWL) Shift with AOICWL Shift with AOICWL = f ( AOI)

100

1050

90

0°

80

1025

70

CWL for 0°

40
30

975
950

20

925

10

wavelength [nm]

0
600

700

800

900

1000

1100

CWL [nm]

50

1000

R [%]

60

900

Rule of thumb
AOI 0° → 45°→ Δλ CWL ~ -10 %

1200
875

100
850

90

45°p 45°s

80

825
800

40
30

775
750

20
10

AOI [°]
0

700

800

900

1000

1100

1200

CWL s-pol. = CWL p-pol. for the same AOI

60

Rmax (λ) = f ( AOI)

100

0°

95

99.96

980

1030

1080

1130

Rmax [%]

R [%]

99.98

99.94
99.92

92

99.90

91

99.88

90

99.86

89

99.84

88

99.82

87

99.80

86

0

Rs [%]]R p [%930][%

CWL for 0°

CWL for 45°

45°s

wavelength [nm]
880

100

96

93

99.1
830

0°

Rs [%]

97

94

99.2

99
780

45°s

98

Rmax

45°p

80

99

Rmax

99.3

70

Rp

Rmax

99.7

184

50

Effects of increasing AOI→ HR-range shifts to shorter wavelengths→ Wider HR s - range→ Narrower HRp- range→ Increasing R s at the CWL→ Decreasing Rp at the CWL

99.8

99.4

40

Split-Up of s- and p-Polarization
45°p

99.9

99.5

30

Modification of Spectral Properties

100

99.6

20

Please note that the plots shown here are numerical results.
The actual values may change if different methods are used.
However, the overall behavior, including the rule of thumb,remains the same.

wavelength [nm]

0
600

10

Rmax [%]50

CWL for 45°

60

R [%]

70

AOI [°]
0

10

5

10

20

15

20

30

25

40

30

35

50

40

45

60

AOI [°]
70

80

Knowhow
Weakly Curved Substrates

Weakly Curved Substrates
LAYERTEC Convention
LAYERTEC applies a marker to the outer cylinder of weakly curved substrates. This allows a reliable identification of both sides. As shown
below, the marker points to either the curved, the weaker curved or the concave surface (depending on the general shape of the substrate). It is only applied for radii of curvature R > 1000 mm.
LAYERTEC marker conventions of weakly curved substrates

Substrates with a plane and a spherical
Substrates
Substrates
with
with
with
aaplaneplane
a plane
and
and
and
aa a
surfaceSubstrates
spherical
spherical
spherical
surfacesurfacesurface
MarkerMarkerpointspointspointstotothetothethecurvedcurvedcurvedsurfacesurfacesurface
MarkerMarker
pointstothecurvedsurface

Substrates with two parallel spherical
Substrates
with
two
spherical
surfaces
Substrates
Substrates
Substrates
with
with
with
two
two
two
spherical
spherical
spherical
surfaces
surfaces
surfaces
Substrates
Substrates
Substrates
with
with
with
two
two
two
parallelparallelparallelsurfaces(Meniscus
Lenses)MarkerMarkerMarkerpointspointspointstotothetothethesurfacesurfacesurface
with
with
with
the
thethelargerlargerlargerspherical
spherical
spherical
surfaces
surfaces
surfaces
(Null
(Null
(Null
Lenses)
Lenses)
Lenses)Markerpointsto thesurfacewiththelargerradiusradiusradiusofofcurvatureofcurvature
curvature
(i.e.
(i.e.
(i.e.
the
thetheweakerweakerweakercurvature)
curvature)
curvature) Marker
MarkerMarkerMarkerpointspointspointstotothetothetheconcaveconcaveconcavesurfacesurfacesurfacepointsto theconcavesurfaceradius of curvature (i.e. the weaker curvature)
1100010000
CX
CX CX

1100
55
0100C5C0C CC
22000200C0C
X0X CX

1100010000
CC
CC CC

Visual Identification

1100010000
CX
CX CX

X0X CX
C
000C5
55
1100
1

1111
00101
C0
C0
X
X CX

1111
00101
C0
C0
C
C CC

CC C CCC
1100010000

1155
00105C0C0C CC

Finding the Plane Side• Hold optical element close to your eye.
• Watch the reflection of the pattern in the optical surface(focusing to a long distance).
• Reflected pattern is blurred → curved side is up• Reflected pattern is clear → plane side is up

Is the Substrate Wedged?
• Watch pattern through optical element.
• Rotate optical element around surface normal.
• Pattern shifts with respect to surrounding area → opticalelement is wedged• No shift → no wedge is present

185Knowhow
Surface Form Tolerances

Surface Form Tolerances
Target Surface vs. Machined Surface

Syntax3/ A(B/C) RMSt < Dt; RMSi < Di; RMSa < Da; λ = E

urf
ac
e

z

Machined surface– target surface= surface form deviation

ce

m
ac
hin
ed
s

targ
et
su
rfa

Surface Form Parameters

Syntax Example

Surface form deviation

Example0.6

z [µm]

0.5
0.4
0.3

tilt

rf
su

0.2

ac

0.1

e

fo

0

rm

–0.1
–0.2

A = Sagitta error ^= PV of best-fit sphere; [nm] or [fringes]
B = PV of irregularity; [nm] or [fringes]
C = PV of rotationally invariant irregularity; [nm] or [fringes]
Dt = RMS of sagitta error; [nm] or [fringes]
Di = RMS of irregularity; [nm] or [fringes]
Da = RMS of rotationally variant irregularity; [nm] or [fringes]
E = Reference wavelength for fringe spacing; [nm]devia

3/ 2(1/0.5); λ = 632.8 nm

A = 2 fringe; B = 1 fringe; C = 0.5 fringe; 1fringe = 0.5×632.8 nm = 316.4 nm

3/ –; RMS t < 100 nm;
RMS i < 30 nm

Dt < 100 nm; Di < 30 nm

Fringes to λSagitta error = surface form deviation – tilt (best linear rms fit)z [µm]

0.2
0.1
03/ – (1); RMS a < 0.1

tion

Dt = RMS (sagitta error); A = PV (best-fit sphere)

0.3

Meaning

B = 1 fringe = 1×λ/2 = 0.5×546 nm= 273 nm; Da < 0.1 fringe

best
-fit
sph
ere

A

Fringesλλ = 546 nm

1 fringe
0.5 fringe
0.2 fringe
0.1 fringe
0.04 fringe

λ/2
λ/4
λ/10
λ/20
λ/50

273 nm136.5 nm
54.6 nm27.3 nm10.92 nm

sa g

–0.1

it t

a

er

–0.2
–0.3

ro r

If tolerances are specified without a unit they are given in fringes. According to ISO 10110-5:2016-04 the reference wavelength always has to be specified.
Please note that in older versions of the standard λ = 546 nm(Hg e-line) is assumed if no reference wavelength is specified.

Dt = RMS (sagitta error); A = PV (best-fit sphere)

Irregularity = Sagitta error – best-fit sphere (rms crit.)
0.25

z [µm]

0.20

ic.

0.10

mm
etr

0.05

–0.10

sy

0

a

t.

–0.05

rt
pa

y
arit
gul
irre

0.15

r ot

B

Basic Rules

How flat is flat?
A flatness of λ/10 on a substrate 6“ in diameter is equal to

C

–0.15
–0.20

Di = RMS (irregularity); B = PV (irregularity); C = PV (rotat. symm. part)

Rotat. variant part = irregularity – rotat. symm. part (rms crit.)
0.15

z [µm]

0.10

ro

0.05

tio
ta

n

al

0
–0.05

ly

var

ia nt part

–0.10
–0.15

Da = RMS (rotationally variant part)

Only sectional views of the 3D optical surface are shown above.

186

the size of a football on Germany.

Knowhow
Surface Imperfection Tolerances

Surface Imperfection Tolerances
SyntaxExample5/ N × B; C N × B; L N × F; E D

5/ 3 × 0.063

A = Defect area [mm2]B = √A (grade number) [mm]
D = Length of edge chips [mm]F = Width of a scratch [mm]N = Number of imperfections

C = Coating
E = Edge chips
L = Scratch

Maximum of 3 imperfections on the surface with a maximum
area A ≤ 0.063 × 0.063 mm2 each. Each permissible defectmay be replaced by smaller ones with Atotal = A1+ A2+A3 +…
as long as the total area does not exceed N × B2 mm2 (here:
3 × 0.0632 mm2).

test area ø e

Lsurface defects c raSyntaxtc hedge chip E

Meaning

Example5/ N×B

Imperfections of the
final surface (uncoatedor coated)

5/ 2 × 0.01

5/ N×B; C N×B

All imperfections of thesurface; Imperfectionsof the coating only

5/ 4 × 0.025; C 2 × 0.063

5/ L N×F

Additional scratches(length > 2 mm)

5/ L 3×0.1

Additional edge chips

5/ E 1.0

5/ E DNot considered are defects with areas equal to or smaller
than A = (0.16 × 0.063)2 mm2.
Defects may be replaced by smaller ones as long as the specified
total defect area is not exceeded: Atotal= ∑ Ai < N × B2.
i
Defects with grade numbers equal to or smaller than 0.16 × B are
not considered.

Why to use ISO 10110 rather than MIL

Surface imperfections in this catalog are specified for coatedsubstrates. For more information regarding specification of
surface imperfections, especially long scratches and edge chips,
please see »LAYERTEC‘s Guide to Optical Coatings and Optics.«

MIL: s/d 20 – 5→ max. scratch width < 0.02 mm→ max. dig size < 0.05 mm
Only dimensions are specified, not numbers of digs/scratches.
With regard to the MIL standard there is »confusion
regarding physical sizes of scratches and digs of a given
number.« Especially, there is »no consensus interpretation
among U.S. optics vendors for the scratch spec.«

Digs and Scratches < 2 mm

5/ N × B

ISO 10110: 5/ 3 × 0.05 L 1 × 0.02

N = Number of imperfections (digs, scratches withlength < 2 mm, local substrate imperfections)
B = Grade number = √A [mm]; A: defect area [mm2]		 Preferred values for laser optics (not specified
by ISO 10110):
B = 0.16, 0.1, 0.063, 0.04, 0.025, 0.016, 0.01

surface defect (dig)scratch withlength < 2 mm

→ no more than 3 digs with max. size < 0.05 mm→ no more than 1 scratch with max. width < 0.02 mm(scratches with a length below 2 mm are considered as digs)
In contrast, ISO 10110 also includes the maximum number of
permissible surface imperfections.
»ISO 10110 is intuitive and easy to understand (regarding) inclusions« as well as »clear and unambiguous (with respect to)surface imperfections«.
Wang et al.; Implementation of ISO 10110 optics drawing standards for the national ignition facility; SPIE, 3782:502-508; 1999

187

KnowhowLaser-Induced Damage Threshold (LIDT)

Laser-Induced Damage Threshold (LIDT)
Short Pulses – Pulse Length Scaling

LIDT in W/cm or W/cm2
CW LASER

1Long pulse with high average power• Absorption because of impurities, structuraldefects and intrinsic material properties:→ Local heating→ Thermal destruction• LIDT is determined by melting point, heat transfer,
purity of the coating

10–1

LIDTcw [kW/cm2 ] ~ 10 LIDTlong pulse [J/cm2 ]10 –7

100 ns10 –8

Scaling of LIDT test data to another pulse
P in an error of upP to 25 %.
duration
I =mayqt qresult
E = qA
A
AtR
AR

LIDT
10 –9

SHORT PULSE

pulse
duration [s]LIDT in J/cm2

Long Pulse and cw-Lasers

10 –10√τ→

20 ps ≤ τ ≤ 100 ns

LIDT1 ≈ LIDT0

τ1τ0τ = Pulse duration

Ref.: Stuart, B.C., et al.; Laser-induced damage in dielectrics with nanosecond to subpicosecond pulses; Phys. Rev. Lett., 74, 2248-2251; 1995

100 ms20 psbeam powerP=beam diameterdeff

deff = 2
10 –2

P
π Emax20 ps

E = 50 MW/cm2(=Absorption: 5 ppm)

LIDT in J/cm2 or W/cm2

P = 10 kW

P = 50 MW

F = 625 kW/cm

F = 44 000 kW/cm

Focus ø = 160 µm

Focus ø = 1.13 cm

Q̇ = 50 mJ/s

Q̇ = 250 J/s

Towards shorter pulses intensity becomes the
crucial quantity for LIDT.

10 –12

beam powerP=beam diameter
deff

ULTRA-SHORT PULSEF=

P
π Emaxdeff = 2

deff = Effective beam diameter [cm]Emax = Maximal power density [W/cm2]
10 –5

10 –13

109
108

LIDT Eth [W/cm2]

10

10

P P
I= q
I t=qq
A t qAA t RA t R

Fluence [J/cm2]:P P
E = EqA= qA
AR AR

qA = Lateral beam quality factor
qt = Temporal beam quality factor
τ1 τ1
ALIDT
= Halfwidth
area→ LIDTLIDT
LIDT√τ
√τ →≈ LIDT1 ≈ 1LIDT00
τ0 τ0
P = Average beam power
R = Repetition ratet = Half width pulse duration
Quality factors for stating of LIDT values• Temporal pulse shape qt: fraction of energy within
temporal FWHM
• Lateral beam shape qA: fraction of energy withinlateral FWHM

–6

F=

106

F=
5

10

F=
F=

104

10 –7

188

Intensity [W/cm2]:

Comparison of fs-LIDT values, measured with different
setups, can be critical because each fs setup has a very
unique pulse shape.

107
10

Short pulse with high peak pulse power• Absorption because of transfer of electrons fromvalence band to conduction band:→ Ionization→ Electronic destruction• LIDT is determined mostly by band gap,
i.e. material properties

10 –11

Sufficent heat transport Heat buildup caused bywithin the substrate – insufficient heat transportcomponent withstands –2 component is thermally 2
LIDTcw [kW/cm ] ~ 10 LIDTlong pulse [J/cm ]the laser beam.
destroyed.

LONG PULSE

10 –4

Ultra-Short Pulses – Temporal Pulse Shape

LIDT in J/cm2 or W/cm2

F=

10 –3

10 –11103
100 ns

1

10

100

10

10
0

1M

W/
cm

kW
/cm

10

kW
/cm

1k
W/
cm
Beam diameter [μm]1 000

10 000100 000

1–14

Beam diameter is important• LIDT is usually normalized to beam spot area, but
a larger beam will likely illuminate more defects.
This may result in a smaller damage threshold.

KnowhowGroup Delay Distortion (GD & GDD)Group Delay Distortion (GD & GDD)Group Delay Dispersion (GDD)
BasicsThe velocity of each wavelength lambda is a function of therefractive index n.

c0
n (λ)

v (λ) =

Result
The propagation of a compressed laser pulse through a dispersive medium (gasses, crystals, glass,…) will change thetemporal pulse shape.

Reference pulse

c0 = Speed of light in vacuumn = refractive indexv = velocity
Example (Sapphire)
Example (Sapphire)

Group Delay (GD)

medium

1.78
1.76
1.74

temporal shift

1.72

Group Delay Dispersion (GDD)
500

600

700

800

900 1000 1100 1200 1300 1400
medium1.70
300 400

wavelength [nm]stretching of temporal envelope

GDD > 0 (Normal Dispersion)→ Shorter wavelengths propagate slower than longer wavelengths (»red is faster than blue«)

mediumrefractive index n

1.80

As you can see in the example above, longer wavelengths are
faster than shorter ones. This is called »normal dispersion«.

GDD < 0 (Anomalous Dispersion)→ Shorter wavelengths propagate faster than longer wavelengths (»blue is faster than red«)1

189Knowhow
How to Mount Optics

How to Mount Optics
How to Mount Optics
While mounting optics mechanical stress is introduced into
the substrate, which in turn can deform the mirror surface.
3-point mount without tightening
Optics whithout stress, but it might fall out if tipped.

3-point mount with excessive tightening
Optics with too much mechanical stress.

3-point mount with appropriate tightening
Best option. LAYERTEC recommends to reduce the thightening of the grub screw slightly after mounting and positioning
the optics.

TAKE CARE WITH RING MOUNTS!
By using ring mounts, you can damage your optics. Even small friction
can splinter the coating and render it unusable. Optics in a ring mount
may also seize up easily during assembly.

190

Knowhow
Cleaning of Optical Surfaces

Cleaning of Optical Surfaces
Workspace

Cleaning
clean workspace,e.g. flow box

optical cleaning tissue(LAYERTEC recommends
Whatman®)

1. First fold new tissue along the long side several times.
Then fold across until you have a round edge.

non-slip tweezers(e.g. with cork)

spectroscopy grade
acetone in a suitablebottle2. Moisten tissue with acetone. Only
moist, not dripping wet. Otherwise, there will be streaks.

air blower
latex/nitrile gloves(powder free)Precleaning

1. Clean hands with soap.

3. Grab moistened tissue or use
tweezer. Hold sample with second tweezer. Slide tissue from oneedge of the sample to the otheronce.

2. Dry hands.

4. Do not use the same part of thetissue again. Turn tissue inside out(at most once!). If the surface is notclean then, use a new tissue.

Attention: Use acetone only for sputtered surfaces!

Little Hints
3. Use appropriate gloves.

4. Blow off dust from all sides.

5. Moisten tissue with acetone. Do notcontaminate the bottle! Compared toalcohol, acetone is the better solvent.
It evaporates quickly and thus reduces
the formation of streaks significantly.

6. Remove coarse dirt from edge andchamfer of substrate.

• Fingerprints on sputtered coatings:
Moisten surface by breathing on
it, slide acetone-moistened tissue
over surface as long as water film
is still visible. – Never do this withhygroscopic substrates (CaF2 ,…)!
• Clean concave surfaces using a lessfolded tissue that can be slightly
bent in the center. Use your thumbto gently press the tissue onto thecurved surface.
• When cleaning, fix small samples
on a concave support (polished,clean glass) using tweezers.
• Store samples on concave polished glass support that has beencleaned using tissue + acetone.

191

CompanyCompany

Chapter Index
History............................................................................193
The Founding Story..............................................................193
Technological Evolution........................................................194
General Terms and Conditions of Sale (Effective
01/04/2016)....................................................................197
Payment and Shipment...................................................202
Volume Discount..................................................................202
Payment Methods................................................................202
Shipment Terms and Costs...................................................202
Imprint............................................................................203

192

Company
History

History
The Founding Story
LAYERTEC (optische Beschichtungen) GmbH is the first spin-off from the Friedrich Schiller University in Jena after the political changes in
East Germany. The founder of the company, Hartmut Heyer, studied physics in Jena between 1976 and 1981. Until 1989 he worked as ascientific assistant on the technology of sputtering for the production of oxide coatings for optical applications. The basis for these developments were the novel PPS5 magnetron sputter sources of the Manfred von Ardenne Institute in Dresden.

Figure 1: LAYERTEC in 1990

Figure 2: Hartmut Heyer (founder) and Dr. Peter Zimmermann(first employee), 1992

Hartmut Heyer succeeded in several groundbreaking developments:• Semi-reactive process control for the production of oxidic layers from the metal target• RF-excited plasmas for sputtering from oxidic targets• Optical monitoring of the layer thickness through the magnetron source and the plasma
This enabled Hartmut Heyer to produce the first complex, low-loss interference coating systems for laser applications starting around1986. VEB Carl Zeiss Jena first introduced HeNe lasers in orange and green around that time. The resonator mirrors were manufactured by
Hartmut Heyer using the new technology.
In 1986, Hartmut Heyer had purchased an old homestead in Mellingen, a village between Jena and Weimar. In 1990-91, the first laboratory
rooms were set up in two garages in the adjoining property (a former butcher’s shop). In January 1992, the production of custom products for research and development started, initially for customers in Germany. In 1994, LAYERTEC was awarded the Innovation Prize ofGerman Medium-Sized Businesses. Starting as a one-man operation, LAYERTEC has developed into a globally active company with about
400 employees today.

Figure 3: LAYERTEC today (in 2022)

193

Company
History

Technological Evolution
1990 – 2000
Optical interference coating systems usually consist of a carrier(e.g. a Fused Silica substrate) and a single- or double-sided coating.

Starting in 1997, it has been possible to customize and supplement
the classic production chain (substrate production-cleaning-coating-packaging). Since then, coating is no longer necessarily the lastprocess step in production. For example, low-cost miniaturized,
fully coated optics have been added to the portfolio. Here, thesmallest parts are diced or drilled out of large coated plates andcleaned fully automatically.

Figure 4: Different laser mirrors

In 1992, LAYERTEC started the production of magnetron sputteredcoating systems. At the beginning, the substrates were bought externally. In 1993, the company started to build up its own substrate
production with experienced precision opticians from the former
VEB Carl Zeiss Jena. The complete production chain has been inplace since 1994, making it possible to manufacture high performance optics from a single source, starting with the raw glass.
In 1995, evaporated systems made of fluoride and oxide materials
for UV applications were sold for the first time.

Figure 7: Diced plate

LAYERTEC has always manufactured single pieces for universities
and other research institutions. For better marketing an online
store was established in 1998.
Coating technologies have been continuously improved since thecompany was founded. Thus, extremely low-loss interference
coating systems could increasingly be produced and components
for high power lasers became a core competence.
Dispersive mirrors were produced for customers from Vienna for
the first time in 1997/98. LAYERTEC developed corresponding calculation software and commissioned, among others, the Fraunhofer ILT Aachen with the construction of several GDD measurement set-ups.

Figure 5: Large optics ultrasonic cleaning process

Further innovations were clean room capable packaging systems
and an automated ultrasonic cleaning of coated and uncoatedsubstrates.

Figure 8: Small laser mirror

194

Figure 6: Packaging of LAYERTEC opticsCompany
History

2000 – 2010
In 2002, the company moved to its current location. Around 2005,
there were considerations to produce coated optics up to approx.
600 mm in diameter. An inline sputtering system was set up tocoat substrates of this size in 2007. Due to the high flatness requirements of large mirror substrates, it was not possible to useclassic planar or spherical grinding and polishing processes. Therefore, zonal polishing was established as a manufacturing technology for the correction of plane surfaces.

This technology enables the production of aspheric surfaces. A
special process development and the corresponding metrology
were required. LAYERTEC has been able to manufacture and measure aspherical substrates in-house from around 2012.
In 2007, the first IBS coating machines (Veeco) were integrated
into the manufacturing process.

Figure 9: Off-axis parabolic mirror

2010 – 2023
Between 2010 and 2012, the production space was expanded byseveral new buildings. Since 2010, LAYERTEC has been investingheavily in technological expertise and the associated developmentof suitable instruments in the fields of metrology, optics production
and ultrasonic cleaning. Based on this expertise, a large number of
unique measurement set-ups were created for the characterizationof optical properties in the ppm range. Reflectance and transmittance can be measured by several CRD setups. Absorption losses
can be determined by PCI. Moreover, an automated defect control
system was developed which enables LAYERTEC to characterizepolishing and coating defects according to ISO 10110.

In 2015, LAYERTEC began to laser engrave all finished Fused Silica
components.

In 2013, the entire production control system was converted to
SAP in order to efficiently manage the large number of products.
In 2010 and 2012, LAYERTEC installed modern IAD plants which
are mainly used for the coating of large optics for high power ultrafast lasers and for line beam optics. Since 2017, LAYERTEC has
been meeting the demands of the industry to produce optics with1.20 m edge length. For this purpose, the machinery was greatly
expanded to include manufacturing, ultrasonic cleaning and thecorresponding metrology.

Figure 11: Laser engraving on different mirror sizes

Around 2018, the technological competence was acquired tochange the shape of glass substrates also with ultrasonic technologies or to produce new geometries.

Figure 10: Large scale optic
Figure 12: Conical hole, drilled in a Fused Silica substrate

195

Company
History

Due to the customer’s wish to use substrates or assemblies withincreasing complexity, LAYERTEC started to invest into joining
technologies and bonding of surface-activated polished surfaces
in 2017. Since then, various joining technologies have been established: optical contacting, adhesive bonding, laser micro welding
for unique parts and series production.

LAYERTEC’s solderable coatings support customers in easily joining miniaturized optics.

Figure 17: Solderable coating on the side of a lensFigure 13: Retroreflector

High finesse cavity mirrors for the NIR and VIS spectral range weredeveloped between 2018 and 2021. LAYERTEC is able to design
and produce such mirrors also with two or three spectral regionsof high reflectance.

Figure 14: Laser welded beam splitter

New technologies were being tested, including lift-off processes
for structuring optical functional surfaces.

Figure 18: Low loss optic

Also, during the Corona pandemic, LAYERTEC always remained
a trusted partner for all customers from industry and research.
By concentrating all the manufacturing steps in one facility thecompany could overcome the shortages in the international supply
chains.
In 2021, LAYERTEC manufactured more than 250 000 coated laser optics from Ø 1 mm to 1.20 m in length for more than 650
customers worldwide.
From 2018 to 2022, LAYERTEC planned and built a new facility
with more than 6 000 m² of production space to reorganize theentire production.
Figure 15: Lithographically structured optic

Filigree carrier structures are being produced to reduce weight.

Figure 16: Scanning mirror with lightweight structures on the rear side196Company
General Terms and Conditions of Sale (Effective 01/04/2016)

General Terms and Conditions of Sale (Effective 01/04/2016)
I.

Scope

1.1 The General Terms and Conditions of Sale set out in the following shall apply to all products and services to be provided by LAYERTEC GmbH (hereinafter called »LAYERTEC«). These General Terms and Conditions of Sale shall apply only to contracts with entrepreneurs in the sense of section 310 para. 1 BGB (German Civil Code) in conjunction with section 14 BGB.
1.2 Unless LAYERTEC has expressly agreed to them, any customer’s general terms and conditions shall not become part of the contract.
This shall apply also where LAYERTEC has not expressly contradicted, or where it performs deliveries or services without having
contradicted, the customer’s general terms and conditions.
1.3 These General Terms and Conditions of Sale shall be valid for deliveries and services in conjunction with the acknowledgement of apurchase order or a quotation by LAYERTEC.
1.4. The contract language shall be German. These General Terms and Conditions of Sale are made available in both German and English.
In case of any discrepancy in the meaning of individual stipulations the German language version shall take precedence exclusively.

II.

Binding Agreement / Article of Sale / Copyright / Samples – Free Issue Materials

2.1 Unless expressly stated otherwise, any offer made by LAYERTEC shall be subject to confirmation and not binding and be merely
construed as inviting offers to purchase/purchase orders from the customer.
Insofar as LAYERTEC makes any binding quotation to the customer and unless stated otherwise by LAYERTEC in any given case,
LAYERTEC shall be bound by its quotation for one month from the quoting date. The contract shall be deemed agreed upon andbinding if the customer accepts the LAYERTEC quotation within the acceptance period. In this case, following acceptance by thecustomer, LAYERTEC shall send to the customer a written acknowledgement of the order.
2.2 Where a customer submits to LAYERTEC an offer to purchase without being in receipt of any LAYERTEC quotation, LAYERTEC may
on the basis of these General Terms and Conditions of Sale accept the customer’s purchase order within one month of receipt of theorder at LAYERTEC. In general, this is done by means of a written acknowledgement of the order.
2.3 The subject of the delivery or service to be provided by LAYERTEC is the product named in the order acknowledgement by LAYERTEC and in the specifications referred to in the acknowledgement.
Any publicity brochures or similar information on the homepage of LAYERTEC, etc., and documentation or performance characteristics on which the offer or the order acknowledgement by LAYERTEC is based, such as figures, drawings, information as to dimensions and weight or intended process technology for the deliveries and services of LAYERTEC as a rule constitute approximations
only and are not binding, unless they are expressly declared binding. Properties of any samples or patterns, etc., shall only become
part of the contract where this is expressly agreed upon. The customer shall have no right to pass on any samples or patterns, etc.,
unless LAYERTEC has given its consent or performance of the contract necessitates it.
2.4 To the extent that LAYERTEC has not by contract or under compelling statutory regulations expressly granted to the customer
any rights to figures, drawings, software, cost estimates, knowhow, or other data and materials (collectively »information«), LAYERTEC shall retain any and all rights of ownership and copyright with respect to such information. Without the written consent by
LAYERTEC such information must not be disclosed to any third party and must be safeguarded by appropriate means against any
unauthorised access by third parties. This applies in particular to all “confidential” information. The customer must not use information of LAYERTEC, nor pass it on to any third party, for any purpose other than those agreed upon or assumed in the contract
with LAYERTEC. Furthermore, no information must be passed on without the customer requiring such third party to sign a written
confidentiality agreement in accordance with this section.
2.5 Any provision by the customer of samples for the manufacture of the product or of free issue materials, especially of material to becoated, shall be free of charge for LAYERTEC. On receipt, LAYERTEC will check samples and free issue materials for complete quantity only. LAYERTEC is not obligated to check quality or functionality. Except as stipulated in section IX. LAYERTEC shall not assume
any liability for samples and free issue materials. Any samples and free issue materials not used for the contractual purposes will be
returned together with the delivery of the product purchased.

III.

Delivery / Default / Passing of Risk

3.1 Delivery dates and lead times shall be agreed upon for each case specifically and shall not be binding unless they are expressly stated as »binding«. LAYERTEC will strive to meet any time/date not expressly agreed upon as binding. Lead times shall commence torun on the date the acknowledgement of the order is received, but not before all the details of the execution of the service to berendered or the manufacture of the product have been agreed upon.

197

Company
General Terms and Conditions of Sale (Effective 01/04/2016)

The delivery dates or lead times agreed upon shall slip or be postponed in the event that any industrial action should take place at
LAYERTEC or any of its suppliers relevant to the supply of the product or the rendering of the service to the customer. Also, thedelivery dates or lead times shall slip or be postponed in the event of any unexpected circumstances occurring that are beyond thecontrol of LAYERTEC, e.g. sub-suppliers in delay, late delivery of materials, denial of official shipping permits, government action,
confiscation of the contractual product, unrest, sabotage, lack of material or power, as long as such circumstances are relevant to
the delivery of the product or service to the customer and not attributable to LAYERTEC. In all the above cases leading to extended
lead time or postponed delivery date, the lead time shall be extended or the delivery date postponed by the duration of the impeding
circumstances. This shall also apply where LAYERTEC is in delay with its delivery or service at the time such circumstances occur.
3.2 Should the lead time be extended or delivery date be postponed in accordance with item 3.1 para. 2 by more than three months,
the customer shall have the right to set a reasonable period of grace for LAYERTEC to perform its delivery or service. If LAYERTEC
fails to deliver within the period allowed, the customer shall have the right to terminate such part of the contract as is not yet performed. Should LAYERTEC have delivered part of the contract performance, the customer shall not have the right to terminate theentire contract, unless the customer is not interested in the part already delivered.
3.3 Should the customer request any changes to the product or should changes to the product become necessary in accordance withitem 6.1 or 6.2, the lead time shall be extended or the delivery date postponed by such period of time as is required for making thechange to the product.
3.4 Should the customer delay or fail to perform any action of cooperation necessary on its part for the product or service to be provided, then the lead time shall be extended or delivery date shall be postponed by such period of time as the customer takes torectify the cooperation omitted on its part. Consequently, the grace period shall start at the time the cooperation would have been
due according to the contractual agreement. If no time has been specified for the action of cooperation to be performed the grace
period shall commence with the receipt by the customer of LAYERTEC’s request for cooperation. The grace period ends with thecompletion of the action of cooperation by the customer.
3.5 Unless stipulated otherwise, delivery of the product or service shall be ex works. Unless otherwise agreed upon, LAYERTEC shall at
the customer’s expense purchase goods in transit insurance for reasonable cover at reasonable cost.
3.6 Instalment delivery or service shall be allowed to the extent deemed acceptable to the customer.
3.7 The risk of accidental loss or accidental deterioration of the product shall pass to the customer at the time the product is handed
over to the customer or to the carrier employed by the customer. This shall apply to instalments or consignments as soon as therespective instalment or consignment is handed over.
Should the customer fail to take delivery, the risk of accidental loss or accidental deterioration of the product shall pass to the customer at the time the customer fails to take delivery.
3.8 In the event of culpable failure on the part of the customer to take delivery or perform any other duty to cooperate, LAYERTEC shallbe entitled to claim compensation for the resulting damage, in particular the profit lost including extra expenditure, if any.
3.9 Should LAYERTEC fail to deliver the product or service when due, the customer may set a reasonable period of at least two weeks
within which LAYERTEC is to deliver. Upon futile expiration of such period the customer shall be entitled to terminate the contract.
In this case the customer shall only have the right to claim damages for non-performance if such failure to perform was caused byintent or culpable negligence on the part of LAYERTEC, its legal representatives or agents. Damages for non-performance shall belimited to the loss typically predictable in such case.

IV.

Price and Terms of Payment

4.1 All prices shall be deemed net prices exclusive of value added tax at the current statutory rate. Prices are ex works inclusive of normal
packaging. Unless otherwise agreed upon, the amount invoiced shall be due for payment within 30 calendar days of the date theinvoice is received.
Where the product is modified at the customer’s request, the customer shall bear the resulting costs. Where the product is specifically packaged or insured at the customer’s request, the customer shall bear the resulting costs.
In the event of any increase in material procurement costs, labour costs and costs of fringe benefits, energy costs and costs underenvironmental regulations, LAYERTEC shall have the right to unilaterally raise the purchase price reasonably (section 315 BGB(German Civil Code)) on the proviso that there are more than four months between the signing of the contract and the delivery.
4.2 In the case of export delivery the customer shall bear all taxes, customs duties and dues payable in conjunction with the sales contract outside the Federal Republic of Germany.
4.3 Insofar as the purchase price is not paid by cash deposit LAYERTEC may request reasonable collateral for the payment of the purchase price (e.g. documentary credit, bank guarantee, letter of credit) prior to despatch.
4.4. If and when the realisable value of all the secured claims LAYERTEC is entitled to, including the rights resulting from the extended
retention of title under section V., exceeds the amount of all secured claims in the long term by more than 30 %, LAYERTEC shallrelease an appropriate part of the collateral upon the customer’s request. It shall be LAYERTEC’s choice what collateral to release.
4.5 The customer shall not be entitled to deduct any counterclaim from the amounts payable to LAYERTEC, unless such counterclaim is
undisputed or has been confirmed by final court decision. Moreover, the customer shall not exercise any right to hold back money,
unless its counterclaim is based on the same contractual relationship.

198

Company
General Terms and Conditions of Sale (Effective 01/04/2016)

V.

Retention of Title

5.1 The purpose of the retention of title agreed upon in the following is the assurance of all present and future claims receivable by LAYERTEC from the customer out of any supply or service contracts between the parties hereto (including any current account balance
restricted to this business relationship).
5.2 LAYERTEC retains legal ownership of the product provided to the customer by LAYERTEC until all the secured claims have been paid
up in full. The product, and in its place the goods subjected to retention of title under this contract will be referred to as the reserved
goods in the following.
5.3 The customer shall store the reserved goods for LAYERTEC free of charge. The customer shall treat the reserved goods with careand purchase at its own cost fire, water damage and theft insurance for adequate replacement value cover.
5.4 The customer shall be entitled to process and sell the reserved goods in its normal course of business. The goods must not bepledged or assigned as security.
5.5 Where the reserved goods are processed by the customer, the processing shall take place in the name and for the account of LAYERTEC as the manufacturer and LAYERTEC directly acquires legal ownership or, where the processing involves materials of several
owners or where the value of the processed item exceeds that of the reserved goods, an interest (fractional ownership) in the newly
manufactured goods at the ratio of the value of the reserved goods to the value of the new goods. In case no such acquisition ofownership by LAYERTEC should occur, the customer hereby assigns to LAYERTEC as security its future title or interest at the above
ratio in the new goods.
Where the reserved goods will be united or inseparably mixed with other goods to form mixed goods and any of the other goods areto be deemed the main goods, the customer, to the extent it owns the main goods, shall assign to LAYERTEC proportional interestin the mixed goods at the ratio named in sentence 1. LAYERTEC hereby accepts such assignment.
5.6 In order to provide security in case the reserved goods are sold on, the customer herewith assigns to LAYERTEC the resulting receivables from such purchaser, in proportion to the interest where LAYERTEC owns an interest in the reserved goods. The same shallapply to any other claims in place of the reserved goods or otherwise resulting with respect to the reserved goods, such as insurance
claims or tort claims in the event of loss or destruction. LAYERTEC accepts this assignment.
LAYERTEC grants the customer revocable power to collect in its own name for the account of LAYERTEC the amounts receivable
assigned to LAYERTEC. Should the customer act in breach of this contract, in particular should the customer fail to make payment
when due, LAYERTEC may revoke this power to collect payments and require the customer to disclose to LAYERTEC the amounts
receivable assigned and the respective debtors, to notify the respective debtors of the assignment made, and to provide to LAYERTEC all documentation and information LAYERTEC requires for asserting its claims.
5.7 Should any third party seize the reserved goods, especially by attachment, the customer shall immediately point out to such third
party the legal ownership of LAYERTEC and shall notify LAYERTEC so that it may assert its title rights. To the extent that such third
party should not be able to remunerate the legal and other costs incurred by LAYERTEC in this case, the customer shall be liable topay such costs.
5.8 Should the customer act in breach of this contract, in particular should the customer fail to make payment when due, LAYERTEC
shall have the right to repossess the reserved goods after setting a reasonable grace period for the contractual obligations to be
performed. The costs of transport for the purpose of repossession shall be borne by the customer. Repossession by LAYERTEC of thereserved goods constitutes termination of the contract. Seizure of the reserved goods by LAYERTEC also constitutes termination of
the contract. Reserved goods repossessed by LAYERTEC may be utilised by LAYERTEC. The revenue from such utilisation, after LAYERTEC has deducted a reasonable amount for the utilisation costs, shall be deducted against such amounts as the customer owes
to LAYERTEC. If LAYERTEC terminates the contract because the customer is in breach of contract, especially in default of payment,
LAYERTEC shall be entitled to demand the reserved goods to be returned.
5.9 Should a retention of title clause in favour of LAYERTEC be wholly or partly impossible or ineffective for legal or factual reasons,the customer shall be obliged, at the request of LAYERTEC, to create a legal and effective assurance (e.g. a lien on the object ofpurchase) for LAYERTEC. Should there be a variety of securities to be considered, then LAYERTEC shall have the choice as to what
security is to be registered. LAYERTEC shall decide in its reasonable discretion.
5.10 The customer undertakes not to cause any changes to the specifications of the product without the prior written consent of LAYERTEC and not to attach to it or use in connection with the product any additional equipment not approved by LAYERTEC for as
long as legal ownership of the reserved goods has not yet passed to the customer.

VI. Change to Specifications
6.1 Up to the delivery of the object of purchase LAYERTEC may change specifications of the product as long as such changes are necessary in order to manufacture a flawless product, do not alter essential technical characteristics of the object of purchase and are
deemed acceptable to the customer. Also, the customer shall agree to further changes suggested by LAYERTEC, insofar as these are
acceptable to the customer. Where such changes would cause the purchase price to increase, this shall be agreed upon between
the parties prior to the execution of such changes.
Moreover, up to the delivery of the product, LAYERTEC may change the process technology intended for manufacturing the productat the time the order was placed, insofar as this will not change essential technical characteristics of the object of purchase and suchchanges are deemed acceptable to the customer.

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6.2 Any changes to specifications of the product, of accessories or other services, which prior to their delivery should become necessary
because of statutory regulations or official orders outside the Federal Republic of Germany shall be carried out by LAYERTEC at thecustomer’s expense.

VII. Warranty
7.1 The customer shall check the product immediately on delivery. The customer shall report by written notification any obvious defectimmediately and no later than within seven days of delivery, and any hidden defect immediately and no later than within seven daysof its detection.
7.2 LAYERTEC may at its discretion repair or replace any defective delivery or service within a reasonable grace period. In the event thatsuch repair or replacement should fail twice, the customer may at its discretion reduce the purchase price or terminate the contract.
7.3 Unless otherwise agreed upon, the warranty period for the product including any accessories bought with it is 12 months from thedate of delivery.
No liability shall be assumed for normal wear and tear. Moreover, LAYERTEC shall not be responsible for the applicability of the
product for any particular use or purpose, unless this is expressly agreed upon between the parties. Furthermore LAYERTEC shallnot be liable for any suitability of the product, insofar as the product is not used for its ordinary use, unless this is expressly agreed
upon between the parties.
7.4 LAYERTEC shall not assume responsibility or warranty for any defect or damage to the product, if the customer itself or with thehelp of any third party not instructed or authorised by LAYERTEC has carried out any repair, rectification or installation work on the
product, the customer has failed to observe the manufacturer’s instructions or has used the product inappropriately, unless the customer disproves the substantiated assertion by LAYERTEC that the defect or damage concerned is attributable to and was caused bysuch repair, rectification or installation work by the customer or any unauthorised third party, failure to observe the manufacturer’s
instructions or any inappropriate use etc. of the product.
7.5. Where LAYERTEC provides coating services on materials to be coated or other free issue materials provided by the customer, LAYERTEC shall not be liable for any defect in the coating services insofar as such defect is attributable to the material for coating or
any other free issue material provided by the customer.
7.6 The costs of any unjustified notice of defects by the customer, in particular the costs of inspecting the defect notified, shall be borneby the customer.

VIII. Intellectual Property Rights; Defect of Title
Unless otherwise agreed upon, LAYERTEC shall provide the product free of any third party industrial trademark or copyrights(hereinafter: intellectual property rights). Should any third party lodge any justified claim against the customer for infringement ofintellectual property rights by its contractual use of products or services provided by LAYERTEC, then LAYERTEC shall be liable tothe customer as follows:
8.1. LAYERTEC shall at its discretion and at its own cost obtain the right of use for the products or services concerned or, where deemed
acceptable to the customer, modify or replace the product or services in such a way that there is no infringement of the intellectual
property right.
If this is not possible at reasonable terms for LAYERTEC, the customer shall be entitled to make use of its statutory rights of termination or price reduction. The customer shall not be entitled to claim compensation for futile expenditure.
For any obligation to pay damages refer to section IX.
8.2. The above obligations on the part of LAYERTEC shall not be valid unless the customer notifies LAYERTEC forthwith in writing about
any claim lodged by any third party and all defensive measures and settlement conferences are reserved to LAYERTEC.
The customer shall not have the right to acknowledge to the third party any infringement of intellectual property rights, unless LAYERTEC has agreed to such acknowledgement. In the event that the customer should discontinue the use of the products or services
for mitigation or other reasons, the customer shall be obliged to point out to the third party that its discontinuation of the use does
not constitute any acknowledgement of an infringement of intellectual property rights.
8.3. Any claim on the part of the customer shall be precluded where any infringement of intellectual property rights is attributable to thecustomer or where infringements of intellectual property rights have been caused by design documentation or any other specificdemand made by the customer with respect to the product or service or have been caused by inappropriate use, or by the customer
altering the product or service or using it together with products not supplied by LAYERTEC.
8.4. The stipulations of section VII. shall be applied accordingly with respect to other defects of title. The customer shall have no further
right to lodge any claim beyond those in sections VIII. and VII. against LAYERTEC on grounds of any defect of title.

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IX. Damages
9.1 LAYERTEC shall not be liable in cases of ordinary or slight negligence.
9.2 In the event of gross negligence the liability of LAYERTEC shall be limited to such damage as can typically be expected to occur.
9.3 The disclaimer and limitation of liability under items 9.1 and 9.2 shall not apply where the liability of LAYERTEC is caused by intent,
by the absence of any property promised or guaranteed, by mandatory liability under product liability legislation, injury to life, limb
or health, violation of fundamental contractual obligations (obligations required for the proper execution of the contract and theperformance of which the customer had a right to rely upon) or by any other legally mandatory liability.
9.4 The stipulations in items 9.1 to 9.3 shall also apply to any claims of the customer against employees or agents of LAYERTEC.
9.5 The stipulations in items 9.1 to 9.3 shall also apply where legal representatives or assistants of LAYERTEC have been acting on behalfof LAYERTEC.

X.

Miscellaneous

10.1 Any and all agreements between LAYERTEC and the customer shall be made in writing. Any waiver of this requirement of written
form shall be made in writing only.
10.2 Without the prior consent of the party concerned, both parties to the contract must neither utilise nor disclose to any third party anyof the other party’s trade secrets or confidential information which have become known to them during their business relationship,
unless such trade secret or confidential information is in the public domain. This shall also apply after the execution of this contract.
10.3 This contract shall be governed by the law of the Federal Republic of Germany; the provisions of the United Nations Convention on
Contracts for the International Sale of Goods dated 11/04/1980 shall not be applied.
10.4 The exclusive legal venue for any claims arising out of this contract shall be Weimar, unless there is any statutory exclusive legal
venue. Place of performance for all deliveries, services and payments shall be Mellingen.
10.5 Should any stipulation of this contract be or become void in whole or in part, or should there be any omission in this agreement,
this shall not affect the validity of the remaining stipulations of this contract.

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Payment and Shipment

Payment and Shipment
Volume Discount
LAYERTEC offers a volume discount for standard items from five pieces up.
Table 1: Volume discountPiecesDiscount

From 5 pieces up

5%

From 10 pieces up

10 %From 20 pieces up

20 %Payment Methods
LAYERTEC accepts the following payment methods:• Credit card (VISA, Mastercard)• Wire transfer
LAYERTEC reserves the right to request advance payment.

Shipment Terms and Costs
LAYERTEC ships your components from Germany. If not requested otherwise, UPS delivery service with DPU Standard according to Incoterms 2020 is used. This standard includes the following conditions:• The vendor pays the shipping costs.
• The customer pays duty and taxes.
• The item is fully insured from doorstep to doorstep.
Table 2: Shipping fee by desination

Destination

Shipping fee

Within Germany

20 €European Union (EU)70 €Other countries

100 €The shipping time with UPS worldwide is usually less than 1 week. On request, it is possible to choose another delivery service (e.g. FedEx
or DHL). If you choose another shipping service, please consider that shipping fees and the average shipping time may differ.
Please make sure to mention the complete shipping address of your company or research facility. If available please also disclose the optional VAT-number and the account number of your preferred delivery service.
If you have further questions please feel free to contact LAYERTEC.

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Imprint
Edition:2nd Edition, © LAYERTEC, 2024, January

Phone:+49 36453 744 0

E-mail:info@layertec.de

Internet:www.layertec.deFax:+49 36453 744 40

Phone (US):+1 707 48 10 216

E-mail (US):ussales@layertec.com

Location:

LAYERTEC GmbH
Ernst-Abbe-Weg 1
99441 Mellingen
GERMANY

Images:LAYERTEC GmbH203

Imprint

LAYERTEC GmbH
Ernst-Abbe-Weg 1
99441 Mellingen
GERMANY

204

Phone: +49 36453 744 0
Fax: +49 36453 744 40
E-mail: info@layertec.de
Web: www.layertec.de

Phone (US): +1 707 48 10 216
E-mail (US): ussales@layertec.com