Variable Optical Delay Linew w w . k y l i a . c o m
i n f o @ k y l i a . c o m

VODL

1 – Description
The Variable Optical Delay Line (VODL) is a device that enables a very precise and stable control of an optical
path length up to 12ns.
The product has one input and one output. The optical delay can continuously be tuned thanks to a
micrometer head (manual option) or a motorized actuator (piloted option).
Our VODL products are athermal and don’t need any external control to stabilize the optical path delay.

VODL 300ps or 600ps packaging

2 – Block diagram
micrometer headfor delay tuning
optical output
optical input

Block diagram: VODL

3 – Absolute maximum ratings
Parameter

SymbolMaximal optical input power

OpIn

Storage temperature range

STR

Humidity

RH

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MinMax

Unit

300mW

-1040°C

585%

VODL

Typ.

Remarks/Conditions

Non condensing

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4 – Operating conditions
Parameter

SymbolMin

Operating wavelength

OWR

Operating temperature range

OTR

Typ.

Max

Unit

1520

1625

nm

1035°C

Remarks/Conditions

5 – Specifications
We propose three VODL product ranges:-With 100ps optical delay range. This product is only available with manual version.
With 300ps or 600ps optical delay range. These products are available with manual (micrometerhead) or piloted (motorized actuator) versions.
With 3ns, 6ns, 9ns or 12ns optical delay range. This product is only available with a motorizedactuator.

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VODL

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VODL: Delay Line Interferometers

Parameter

Symbol100ps

Insertion 300ps and 600ps
1Losses
3ns, 6ns, 9ns or 12ns
IL uniformityTyp.

MaxSM0.51.0SM0.5

1.00.81.5SM

1.5

2.0PM

2.0

2.5

PM

1

Polarization Dependant Losses
1,3Optical Return Loss
Manual VODL sensitivity

Motorized VODL

Minimumincremental motion

Relative accuracy

Unidirectional
repeatability

Bidirectional
repeatability

ILΔIL
PDL

1,2

Polarization Extinction RatioMin

VOA sensitivity

Packaging size

0.5dB

Over full delay range

0.3dB

Over full delay range

dB

ORL

35

dB
1.3

300ps

15600ps

30

300ps

3600ps63ns

1012ns

40

300ps

150

600ps

3003ns

250

12ns

1000

300ps

30600ps

60

3ns

30

12ns

120

300ps

40

600ps

60

3ns

150

45ps/turn
fs

fs

fs

The relative accuracy of the VODL is thedegree to which a given displacement
conforms to an agreed upon standard.

fs

The unidirectional repeatability is theability of the VODL to achieve acommanded position over many
attempts when approach from thesame direction.

fs

The bidirectional repeatability is theability of the VODL to achieve acommanded position over many
attempts when approach from either
direction.

600

VOA

0.3

0.5

dB

0.5

1.0

ps

60

56

Over full delay range

20RIL

Variable Optical Attenuation

dB

100ps

1Reference position accuracy

Remarks/Conditions

PER12ns
Reference Insertion Losses

UnitdB
0.05

100ps

100 x 32 x 28

300ps

216 x 92 x 40

600ps
3ns to12ns

216 x 92 x 40

0.1

dBmm

3750 x 400 x 129

1

measured over OTR and OWR for all states of polarizationfor Single Mode VODL
3
for long free space delay option
4for VODL option
5for VOA option
6excluding micrometer head or piloted actuator
2

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VODL

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VODL: Delay Line Interferometers

6 – Piloted versions: motorized actuator or linear stage
For 300ps and 600ps VODL, the piloted version uses a motorized actuator driven by a controller. Thecontroller is compatible with the NEWPORT NSTRUCT Instrument Manager platform, simple and intuitive touse and conveniently accessible via USB.
The 3ns to 12ns VODLs use a motorized linear stage which is driven by a stepper motor controller/driver.
Communication with the controller/driver is via an integrated RS-232-C interface, or a USB port.
All piloted VODL are delivered with a controller, a USB cable and a power supply.

7 – Optical Reference Path (ORP) option
The optical reference path option enables to precisely control the difference between two optical paths andeventually take it down to zero.
Let us call ODR the optical delay range of the VODL (ODR can be 300ps, 600ps, 3ns, 6ns, 9ns or 10ns) and t0
the optical delay of the reference arm. By default the reference arm is set such as the optical delay of thevariable arm can be adjusted in the range [t0; t0+ODR]. However, upon customer request, the reference arm
can be set such as the variable arm can be tuned in the range [t0-ODR; t0] or [t0-ODR/2; t0+ODR/2] or any
other set up.

Reference Line output
Reference Line input
micrometer headfor delay tuning
VODL output
VODL input

t0t0 + ODRVODL with ORP option, [t0; t0 + ORD] version
The reference position accuracy corresponds to the delay difference between the VODL and the reference
arm when the VODL is set to t0. This parameter is better than 1ps.

8 – Variable Optical Attenuation (VOA) option
We propose to add a VOA (Variable Optical Attenuator) on our VODL product.

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VODL4VODL: Delay Line Interferometers

9 – Application note
Using a VODL with ORP and VOA options will help to adjust the skew and the IL uniformity in a DPSK
experimental setup:

DPSK demodulator

differential
photodetector

micrometer headfor IL attenuation(IL uniformity control)

micrometer headfor delay tuning(skew control)

VODL with ORP and VOA options application

micrometer headfor IL attenuation

ORP input andoutput

micrometer headfor delay tuning

VODL input andoutput

VODL with ORP and VOA options

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VODL5VODL: Delay Line Interferometers10 – IL uniformity measurements
Here are the IL measurements for a 300ps VODL over the wavelength range for different delays andtemperatures.
IL (dB)

0-0.1

-0.2

-0.3

-0.4

-0.5

-0.6
delay = 333ps-0.7

delay = 200ps
delay = 67ps

-0.8
delay = 0ps-0.9-1
1510

1520

1530

1540

1550

1560

1570

1580

1590

1600

1610

1620

wavelength (nm)IL (dB)

Graph: IL vs wavelength for different delay ranges
0-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
T = 10°C-0.7

T = 22°C-0.8

T = 35°C-0.9-11520

1525

1530

1535

1540

1545

1550

1555

1560

1565

1570

wavelength (nm)Graph: IL vs wavelength for different temperatures

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VODL

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11 – Fiber type and connectors
Every VODL can be proposed either with SM or PM fiber.
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…).

12 – Wavelength range
VODL can be proposed at different wavelength range, from the visible to the IR. The device will be
operational on a wavelength range of a tens of nanometers centered on the wavelength required bycustomer. VODL at 1300nm, 1064nm and 800nm have already successfully been manufactured.

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

14 – Package layout

Manual VODL 300ps and 600ps packaging

Manual VODL 100ps packaging

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VODL7

VODL: Delay Line Interferometers

15 – Revisiondate
February 21, 2013
May 28, 2014
rdFebruary 3 , 2015

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version
VODL V1.0
VODL V1.1
VODL V1.2

ObjectCreation
Added VODL 100ps
Added VODL 6ns, 9ns and 12ns

VODL8