Delay Line Interferometersw w w . k y l i a . c o m
i n f o @ k y l i a . c o m

MINT and WT-MINT

1 – Description………………………………………………………………………………………………………………………………………
2 – Block diagrams………………………………………………………………………………………………………………………………..
3 – Absolute maximum ratings………………………………………………………………………………………………………………
4 – Operating conditions……………………………………………………………………………………………………………………….
5 – MINT specifications…………………………………………………………………………………………………………………………
6 – MINT statistic data…………………………………………………………………………………………………………………………..
7 – WT-MINT specifications…………………………………………………………………………………………………………………..
8 – Phase tuning options……………………………………………………………………………………………………………………….
9 – ER attenuation option……………………………………………………………………………………………………………………..
10 – IL attenuation option…………………………………………………………………………………………………………………….
11 – Tunable coupling option………………………………………………………………………………………………………………..
12 – TAP option…………………………………………………………………………………………………………………………………….
13 – Second input option………………………………………………………………………………………………………………………
14 – Wavelength range…………………………………………………………………………………………………………………………
15 – Fiber type and connectors……………………………………………………………………………………………………………..
16 – Custom products……………………………………………………………………………………………………………………………
17 – Packages layout…………………………………………………………………………………………………………………………….
18 – Revision…………………………………………………………………………………………………………………………………………

p1
p2
p3
p3
p4
p6
p7
p9
p11
p13
p13
p15
p15
p15
p16
p16
p16
p17

1 – Description
The Micro Interferometer (MINT) is a Delay Line Interferometer (DLI) that performs the interference
between an incoming signal and itself delayed by one bit-time. Dedicated to D(Q)PSK demodulation it can beused in many other applications. MINT is tunable to enable a precise matching of the carrier frequency. Twophase tuning options are available: the ultra-fast option (U), which exhibits very low tuning time constant(20µs), and the low voltage option (L), which needs only 3V to reach the tuning range.
The WT-MINT is a Widely Tunable MINT that enables to set the delay of the interferometer to the desiredvalue. This can be done either with a micrometer head (manual option) or with a motorized translation stage(piloted version). In both case U and L option are available to precisely match the carrier frequency. Thereare three ranges of WT-MINT:- WT-MINT 100ps: it enables to set an optical delay range of 100ps (corresponding to a Free Spectral
Range of 10GHz to infinite, or – for instance – 5GHz to 10GHz). Available with manual or pilotedoption.
- WT-MINT 300ps: it enables to set an optical delay range of 300ps (corresponding to a Free Spectral
Range of 3.3GHz to infinite, or 2.5GHz to 10GHz). Available with manual or piloted option.
- WT-MINT 3000ps: it enables to set an optical delay range of 3000ps (corresponding to a Free
Spectral Range of 0.33GHz to infinite). Available with piloted option only.
MINT and WT-MINT products are also available with PM fibers.

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MINT & WTMINT

1MINT and WT-MINT: Delay Line Interferometers

MINT packaging

WT-MINT packaging

2 – Block diagrams
phase tuning

opticalinput

TIA

RF outputs

differential
photodetector

DPSK demodulator

50/50 plate
mirroroptical connector

Block diagram: MINT

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MINT & WTMINT

2MINT and WT-MINT: Delay Line Interferometers

micrometer head
for FSR tuning

phase tuning

opticalinput

TIA

RF outputs

differential
photodetector

FSR tunable
DPSK demodulator

Block diagram: WT-MINT
The incoming signal is split in two parts. One is delayed regarding the other and then both are recombinedon two outputs where they interfere one with each other. Both outputs are phase shifted by 180° and thus
can be plugged to balanced or differential photodiodes that will convert a phase modulation into an
amplitude modulation.
The delay between both arms of the interferometer should be equal to the time-bit (Tbit) of the incoming
signal. Then the interferometer is characterized by its Free Spectral Range (FSR) which is linked to Tbit by therelation FSR=1/Tbit.

3 – Absolute maximum ratings
Parameter

SymbolMaximal optical input power

OpIn

Storage temperature
range

MINT
WT-MINT

Humidity

Min

STR
RH

Fiber bend radius
Maximum input voltage

Typ.

MaxUnit

300mW-4080-1040

58520U option
L option

Remarks/Conditions°C%

Non condensing

mm100

Vmax

4V

4 – Operating conditions
Parameter

SymbolMin

Operating wavelength

OWR

Operating temperature
range

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MINT
WT-MINTOTRMax

Unit

1520

1570

nm

070

1035

MINT & WTMINT

Typ.

Remarks/Conditions°C

3

MINT and WT-MINT: Delay Line Interferometers

5 – MINT specifications
MINT, FSR > 2.5GHz
Parameter
Free Spectral Range
FSR accuracy

111

Insertion Losses
IL uniformity

11,2

Polarization Dependant Losses
Polarization Dependant
1,2Frequency Shift

FSR>10GHz

SymbolMin

FSR

2.5Typ.

1

Polarization Extinction Ratio

1,3Temperature DependantFrequency Shift

LUU

Tuning time constantPower consumption

LULUGHzAny FSR > 2.5GHz can beprovided

%FSR

IL

2.0dB

ΔIL

0.5dB

PDL

0.3dB

2.0

PDFS

%FSR

4.0
ER

18

PER

20dB
25dB
10TDFS50
1.5

L

Remarks/Conditions

1

Tuning range
Tuning voltage

Unit

ΔFSR

FSR<10GHzExtinction Ratio

Max

3V75

τ

90

FSR

1.0s
ms0.001

Voltage needed to reachthe tuning range

V

0.02
0.5P%FSR

To reach 50% of the finalstateW

Polarization Mode Dispersion

PMD0.1psChromatic Dispersion

CD1

ps/nm

Optical Return Loss

ORL

35dBSkew
Packaging size

0.54

FSR >= 20GHz

44 x 26 x 9.5

FSR < 20GHz
or PM fiber any FSR

100 x 55 x 16

Phase tuning connector
Fiber Pigtail Type

1.0

psmm

30.1 inch PIN header
SM

SMF-28PM

PANDA PM

Fiber Pigtail Length

0.9

1.0

With 900µm loose tube
1.1m

1measured over OTR and OWR for all states of polarizationfor Single Mode MINT
3for Polarization Maintaining MINT
4excluding fiber boot2

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MINT & WTMINT

4MINT and WT-MINT: Delay Line Interferometers

MINT, FSR < 2.5GHz
Parameter
Free Spectral Range
FSR accuracy

MaxUnit

2.5

GHz

ΔFSR

5%FSR

IL19.0dB

1IL29.0dB

1,3PER

11Insertion Losses on short arm

1Insertion Losses on long arm
Polarization Extinction Ratio

Symbol

Min

FSR

0.4

Typ.

20

25
1.5

Tuning time constantPower consumption

LULUL
U3V

7590

τ

FSR

s0.02

ms0.001

Voltage needed to reachthe tuning range

V1.00.5P

Including 6dB of naturallosses due tobeamsplitterdB

Tuning rangeTuning voltage

To reach 50% of the finalstateW

Polarization Mode Dispersion

PMD0.1ps

Chromatic Dispersion

CD1

ps/nm

Optical Return Loss

ORL35dBSkew
Packaging size

0.54

Fiber Pigtail Type1.0130 x 65 x 19.5

Phase tuning connector

Remarks/Conditions
Any FSR between 400MHz
and 2.5GHz can beprovided

psmm

30.1 inch PIN header
SM

SMF-28PM

PANDA PM

Fiber Pigtail Length

0.9

1.0

With 900µm loose tube
1.1m

1measured over OTR and OWR for all states of polarizationfor Single Mode MINT
3for Polarization Maintaining MINT
4excluding fiber boot2

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MINT & WTMINT

5MINT and WT-MINT: Delay Line Interferometers

6 – MINT statistic data
Here are the statistic data of our MINT delivered between January 2009 and March 2013 (any FSR from
2.5Hz to 100GHz, any phase tuning option).
50%% of MINT delivered

25%
20%
15%
10%
5%

40%
30%
20%
10%

< 0.35< 0.3< 0.25< 0.2

PDL (dB)(< 0.3 means 0.3dB > PDL > 0.25dB)

IL (dB)(> -1 means -1.2dB > IL > -1.0dB)
20%

20%% of MINT delivered% of MINT delivered(FSR > 10GHz)< 0.150> -0.2

> -0.4> -0.6> -0.8> -1> -1.2> -1.4> -1.6> -1.8> -2< 0.10%0%< 0.05% of MINT delivered

30%

15%
10%
5%

15%
10%
5%
0%

<0< 0.2< 0.4< 0.6< 0.8<1< 1.2
< 1.4
< 1.6
< 1.8<2< 2.2
< 2.4
< 2.6
< 2.8
<3> 17> 18> 19> 20> 21> 22> 23> 24> 25> 26> 27> 28> 29> 300%

PDFS (%FSR)(< 3 means 3% > PDFS > 2.8%)

ER (dB)(> 18 means 19dB > ER > 18dB)

For PDFS and ER, we do not observe Gaussian repartition because these parameters depend on the FSR(larger is the FSR, better are PDFS and ER).

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MINT & WTMINT

6MINT and WT-MINT: Delay Line Interferometers

7 – WT-MINT specifications
The 100ps WT-MINT allows a tunable FSR from 10GHz to infinite.

WT-MINT, 100ps Optical Delay Range
Parameter

Symbol

Min

Optical Delay Range

ODR

100Typ.

Max

Manual WT-MINT ODR sensitivityMotorized
WT-MINTUnit8fsMinimum incremental motion

2fs

Relative accuracy

75fs

Unidirectional repeatability

15fs

Bidirectional repeatability

20fs

IL

2.5dB

1Insertion Losses
IL uniformity

1
1,2

Polarization Dependant Losses

Polarization Dependant Frequency Shift
Extinction Ratio

1

Polarization Extinction Ratio

1,3

1,2

ΔIL

0.5dB

PDL

0.5dB

PDFS

3.0%FSR

ER

18PER

20dB
25dB

Tuning range

1.5

Tuning voltage
Tuning time constantPower consumption

LUL
ULU

3V75τ90FSRs0.02

ms0.001

Voltage needed to reachthe tuning range

V1.00.5

P

To reach 50% of the finalstate

W

Polarization Mode Dispersion

PMD

0.1

ps

Chromatic Dispersion

CD1

ps/nm

Optical Return Loss

ORL

35Skew
Packaging sizedB
0.54216 x 92 x 40

Phase tuning connector
Fiber Pigtail Type

Remarks/Conditions

ps

1.0

ps
mm

3

BNC
SM

SMF-28PM

PANDA PM

With 900µm loose tube

1

measured over ODR, OTR and OWR for all states of polarizationfor Single Mode WT-MINT
3
for Polarization Maintaining WT-MINT
4excluding micrometer head or piloted actuator
2

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MINT & WTMINT7MINT and WT-MINT: Delay Line Interferometers

The 300ps WT-MINT allows a tunable FSR from 3.3GHz to infinite or 2.5GHz to 10GHz.

WT-MINT, 300ps Optical Delay Range
ParameterSymbol

Min

Optical Delay Range

ODR

300Typ.

Max
15

fs

Minimum incremental motion

3

fs

Relative accuracy

150

fs

Unidirectional repeatability

30

fs

Bidirectional repeatability

40

fs

IL

4.0

dB

ΔIL

1.0dB

PDL

0.8dB

PDFS

5.0%FSR

1Insertion Losses
IL uniformity

1
1,2

Polarization Dependant Losses

Polarization Dependant Frequency Shift
Extinction Ratio

1

Polarization Extinction Ratio

1,31,2ER15PER20dB
25dB

Tuning range

1.5

Tuning voltage
Tuning time constantPower consumption

LULULU3V75

τ90

FSRs0.02

ms0.001

Voltage needed to reachthe tuning range

V

1.00.5P

To reach 50% of the finalstate

W

Polarization Mode Dispersion

PMD

0.1

ps

Chromatic Dispersion

CD1

ps/nm

Optical Return Loss

ORL

35Skew
Packaging sizedB
0.5

4216 x 92 x 40

Phase tuning connector
Fiber Pigtail Type

Remarks/Conditions

ps

Manual WT-MINT ODR sensitivity
Motorized
WT-MINT

Unit1.0psmm

3BNC
SMSMF-28

PM

PANDA PM

With 900µm loose tube

1

measured over ODR, OTR and OWR for all states of polarizationfor Single Mode WT-MINT
3for Polarization Maintaining WT-MINT
4excluding micrometer head or piloted actuator
2

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MINT & WTMINT

8MINT and WT-MINT: Delay Line Interferometers

The 3ns WT-MINT allows a tunable FSR from 0.33GHz to infinite.
The 12ns WT-MINT allows a tunable FSR from 83MHz to infinite.

WT-MINT, 3ns to 12ns Optical Delay Range
Parameter

Symbol

Min

Optical Delay Range

ODR

3000

Minimum incremental
motionRelative accuracy
Unidirectionalrepeatability
Bidirectional repeatability

Typ.

1012ns delay

40

3ns delay

250

12ns delay

1000

3ns delay

30

12ns delay120

3ns delay

150

12ns delay

600

1Power consumption

fs
fs

9.0

dB

IL2

9.0

dB

1,2

PER

25

Tuning range

Tuning time constant

fsIL120U
LU
L
U

3V75

τ

90

FSR
V

1.0

s

0.02

ms

0.5

P0.001

PMD

0.1

ps

Chromatic Dispersion

CD

1

ps/nm

Optical Return Loss

ORL

35

1
2

1.0

ps

750 x 400 x 129

Phase tuning connector
Fiber Pigtail TypeTo reach 50% of the finalstatedB0.5

Packaging size

Voltage needed to reachthe tuning range

WPolarization Mode Dispersion

Skew

Including 6dB of naturallosses due tobeamsplitter

dB1.5

L

Remarks/Conditions

fs1

Insertion Losses on long arm
Polarization Extinction Ratio

Unit
ps3ns delay

Insertion Losses on short arm

Tuning voltage

Max

BNC
SM

SMF-28PMPANDA PM

With 900µm loose tube

measured over ODR, OTR and OWR for all states of polarization
for Polarization Maintaining WT-MINT

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MINT & WTMINT9MINT and WT-MINT: Delay Line Interferometers

8 – Phase tuning options
For DPSK demodulation, the phase tuning is essential in order to control the contrast between both outputsof the interferometer/demodulator.

IL (dB)

Using the phase tuning, theuser can adjust thedemodulator phase inorder to match with theinput signal frequency
input signal
frequency (=c/λ)

FSR

Frequency (GHz)DPSK demodulator
output 1

DPSK demodulator
output 2

low contrast between outputs
high contrast between outputs thanks to phase tuning
The FSR variation is not significant (and can be considered as invariant) when the user adjust the phase ofthe demodulator/interferometer.
KYLIA proposes for all its DPSK demodulators (MINT and WT-MINT) two different phase tuning options:
U option:

Ultra-fast response based on a piezo actuator.
This option is helpful for fast shifting systems (instability of the laser for instance). The DLI
can adapt itself instantaneously to the environment, if a closed loop between BER and phaseshifting is set up. This solution is mainly used in labs.

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MINT & WTMINT

10MINT and WT-MINT:MINT: Delay Line Interferometers

With this option,
ption, the user can accomplish a shift of one FSR by applying a 60V voltage. Thetuning time is better than 20µs.

Tuning speed for a U option DPSK demodulator
L option:

Low-voltage
voltage tuning based on a resistive heater
Phase shift is obtained using a resistiveresist
heater fixed on an optical element. Changing thevoltage changes the local temperature and thus the optical index, then the optical delay.
With this option, the user can accomplish a shift of one FSR by applying a 2V voltage. Thetuning time is better than 1s.

9 – ER attenuation option
It is possible to tune the extinction ratio of an interferometer by adjusting the power in both arms. When thepower is the same the ER will be the greatest. By attenuating the power in one arm, ER will be reduced.
The ER attenuation option for MINT and WT-MINTWT MINT consist of a micrometer head that can adjust the powerof one arm of the interferometer. It enables to tune the ER down to 0dB (one arm is totally shut down) withan accuracy of 1dB.
phase tuning
micrometer headfor ER attenuation

opticalinput

TIA

RF outputs

differential
photodetector

DPSK demodulator

ck diagram: DLI with ER attenuation option
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MINT & WTMINT

11

MINT and WT-MINT: Delay Line Interferometers

IL (dB)On the following graph, we show the variation of the spectral response of our DLI by attenuating the opticalbeam for one arm of the interferometer.
0position (mm)=0
position (mm)=0.05
position (mm)=0.10
position (mm)=0.15
position (mm)=0.20
position (mm)=0.25
position (mm)=0.27
position (mm)=0.28
position (mm)=0.29
position (mm)=0.30
position (mm)=0.31
position (mm)=0.32
position (mm)=0.33
position (mm)=0.34
position (mm)=0.35
position (mm)=0.36
position (mm)=0.37
position (mm)=0.38
position (mm)=0.39
position (mm)=0.40-5-10-15-20-25-30-35-40
193360193370193380193390193400193410frequency (GHz)MINT spectral response with ER attenuation

micrometer headfor ER attenuation

0.1 inch PIN header
for phase tuning

MINT with ER attenuation option

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MINT & WTMINT

12MINT and WT-MINT: Delay Line Interferometers

micrometer headfor ER attenuation

BNC connector
for phase tuning

micrometer head
for FSR tuning

WT-MINT with ER attenuation option

10 – IL attenuation option
IL attenuation enables to increase the IL on each output individually. This can be done thanks to a
micrometer head. The attenuation can be total (no power exits from the output) and adjusted with anaccuracy of 0.1dB.
phase tuning
micrometer headfor IL attenuation

opticalinput

TIA

RF outputs

differential
photodetector

DPSK demodulator

Block diagram: DLI with IL attenuation option

11 – Tunable coupling option
This option is available for PM MINT or PM WT-MINT only. It enables to adjust the splitting ratio of theinterferometer (which is 50/50 for standard interferometers) from 100/0 to 0/100. This can be very useful if
a precise 50/50 ratio is needed.

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MINT & WTMINT

13

MINT and WT-MINT: Delay Line Interferometersphase tuning

tunablecoupler
opticalinput

TIA

RF outputs

differential
photodetector

DPSK demodulator

Block diagram: DLI with tunable coupling option

knob
for tunable coupling

micrometer headfor ER attenuation

micrometer head
for FSR tuning

BNC connector
for phase tuning

WT-MINT PM with tunable coupling and ER attenuation options

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MINT & WTMINT

14MINT and WT-MINT: Delay Line Interferometers

12 – TAP option
Thanks to the flexibility of our technology, we can propose to add optical TAP outputs in our products. The
TAP ratio can be 4% or 50%.

phase tuning
input-TAP
outputoutput-TAP
outputTIA

opticalinput

RF outputs

differential
photodetector

DPSK demodulator

Block diagram: MINT with TAP option for input and output signals

13 – Second input option
A second input can also be added in our product.
phase tuning

opticalinput 1TIA
opticalinput 2

RF outputs

differential
photodetector

DPSK demodulator

Block diagram: MINT with a second optical input

14 – Wavelength range
MINT and WT-MINT can be proposed at different wavelength range, from the visible to the IR 800nm,1064nm, 1300nm…). The device will be operational on a wavelength range of a tens of nanometers centeredon the wavelength required by customer.

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MINT & WTMINT

15MINT and WT-MINT: Delay Line Interferometers

15 – Fiber type and connectors
Every MINT or WT-MINT can be proposed either with SM or PM fibers.
The devices can be proposed with any kind of connectors (FP/UPC, FC/APC, SC/PC, SC/APC, LC/PC, E2000/PC,E2000/APC, etc…).

16 – Custom products
Thanks to our free-space technology we can easily customize most of our products and so it is for the MINTand WT-MINT. Customer can feel free to ask for any customization they need. We will examine the requestand do our best to have a positive answer.

17 – Packages layout

MINT packaging : FSR > 20GHz

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MINT packaging : FSR > 2.5GHz

MINT & WTMINT

16MINT and WT-MINT: Delay Line Interferometers

MINT packaging : FSR < 2.5GHz

WT-MINT packaging (with ER attenuation option)

18 – Revision
dateMarch 21, 2013
May 15, 2014
rdFebruary 3 , 2015

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versionMINT V1.0
MINT V1.1
MINT V1.2

ObjectCreation
Phase tuning option explanation
MINT packaging for FSR < 2.5GHz
Added 12ns delay WTMINTMINT & WTMINT17