EXFO FTB-5500B User Manual
FTB-5500B
PMD Analyzer for FTB-500
User Guide
Copyright © 2003–2009 EXFO Electro-Optical Engineering Inc. All rights
reserved. No part of this publication may be reproduced, stored in a
retrieval system or transmitted in any form, be it electronically,
mechanically, or by any other means such as photocopying, recording or
otherwise, without the prior written permission of EXFO Electro-Optical
Engineering Inc. (EXFO).
Information provided by EXFO is believed to be accurate and reliable.
However, no responsibility is assumed by EXFO for its use nor for any
infringements of patents or other rights of third parties that may result from
its use. No license is granted by implication or otherwise under any patent
rights of EXFO.
EXFO’s Commerce And Government Entities (CAGE) code under the North
Atlantic Treaty Organization (NATO) is 0L8C3.
The information contained in this publication is subject to change without
notice.
Trademarks
EXFO’s trademarks have been identified as such. However, the presence
or absence of such identification does not affect the legal status of any
trademark.
Units of Measurement
Units of measurement in this publication conform to SI standards and
practices.
Patents
The Polarization Mode Dispersion Analyzer is the subject of International
PCT application, publication number WO 2004/070341; EXFO’s Universal
Interface is protected by US patent 6,612,750.
Version number 4.0.1
ii FTB-5500B
Contents
Contents
Certification Information ....................................................................................................... vi
1 Introducing the FTB-5500B Polarization Mode Dispersion Analyzer ......... 1
Main Features .........................................................................................................................1
Typical Applications ................................................................................................................2
Basic Polarization Mode Dispersion Theory .............................................................................3
Conventions ............................................................................................................................6
2 Safety Information ....................................................................................... 7
3 Getting Started with Your Polarization Mode Dispersion Analyzer .......... 9
Inserting and Removing Test Modules ....................................................................................9
Starting the Polarization Mode Dispersion Analyzer Application ..........................................13
Exiting the Application .........................................................................................................17
4 Setting Up the Polarization Mode Dispersion Analyzer ........................... 19
Defining the Automatic Fiber Name Format .........................................................................19
Customizing PMD Value and Coefficient Thresholds .............................................................20
Setting Acquisition Parameters .............................................................................................24
Preparing for Multiple Acquisitions on a Fiber ......................................................................28
Averaging Measurements .....................................................................................................31
5 Operating the Polarization Mode Dispersion Analyzer ............................ 33
Cleaning and Connecting Optical Fibers ...............................................................................33
Installing the EXFO Universal Interface (EUI) .........................................................................34
Setting Up Hardware for Measurements ...............................................................................36
Acquiring Traces ...................................................................................................................39
Performing a Null Measurement ...........................................................................................41
Viewing the Input Power Level .............................................................................................42
Polarization Mode Dispersion Analyzer iii
Contents
6 Managing Results .......................................................................................43
Customizing Graph View ......................................................................................................43
Viewing Acquisition Results and Information .......................................................................44
Removing Unwanted Results ................................................................................................49
Viewing Statistics ..................................................................................................................51
Linking Distinct Fibers to a Single Fiber ................................................................................54
Creating New Result Files with Selected Fibers .....................................................................56
Documenting Results ............................................................................................................58
Defining a Template for Test Information ..............................................................................62
Saving Results Files ...............................................................................................................63
Exporting Results and Graphs ...............................................................................................64
Customizing Reports .............................................................................................................67
Printing Data ........................................................................................................................69
Closing Result Files ...............................................................................................................72
7 Exporting PMD Files with the File Converter ............................................73
Starting and Exiting the File Converter .................................................................................74
Setting Export Parameters ....................................................................................................76
Exporting PMD Files ..............................................................................................................78
8 Maintenance ................................................................................................81
Cleaning Fixed Connectors ....................................................................................................82
Cleaning EUI Connectors ......................................................................................................84
Recalibrating the Unit ...........................................................................................................86
Recycling and Disposal (Applies to European Union Only) ....................................................87
9 Troubleshooting ..........................................................................................89
Solving Common Problems ...................................................................................................89
Viewing Online Documentation ............................................................................................92
Contacting the Technical Support Group ..............................................................................93
Transportation ......................................................................................................................94
10 Warranty ......................................................................................................95
General Information .............................................................................................................95
Liability .................................................................................................................................96
Exclusions .............................................................................................................................97
Certification ..........................................................................................................................97
Service and Repairs ...............................................................................................................98
EXFO Service Centers Worldwide ..........................................................................................99
A Technical Specifications ............................................................................101
iv FTB-5500B
Contents
B Using Third-Party Broadband Light Sources ........................................... 103
Compliance Criteria ............................................................................................................103
Uncertainty Formula ...........................................................................................................105
Index .............................................................................................................. 107
Polarization Mode Dispersion Analyzer v
Certification Information
Certification Information
F.C.C. Information
Electronic test equipment is exempt from Part 15 compliance (FCC) in
the United States. However, compliance verification tests are
systematically performed on most EXFO equipment.
Information
Electronic test equipment is subject to the EMC Directive in the European
Union. The EN61326 standard prescribes both emission and immunity
requirements for laboratory, measurement, and control equipment.
This unit has undergone extensive testing according to the European Union
Directive and Standards.
vi FTB-5500B
Certification Information
DECLARATION OF CONFORMITY
Application of Council Directive(s): 2006/95/EC - The Low Voltage Directive
Manufacturer’s Name: EXFO Electro-Optical Engineering Inc.
Manufacturer’s Address: 400 Godin Avenue
Quebec, Quebec
(418) 683-0211
Equipment Type/Environment: Test & Measurement / Industrial
Trade Name/Model No.: FTB-5500B
Standard(s) to which Conformity is Declared:
EN 61010-1:2001 Safety Requirements for Electrical Equipment for Measurement,
EN 61326-1:2006 Electrical Equipment for Measurement, Control and Laboratory
EN 60825-1:1994 +A2:2001
+A1:2002
EN 55022: 1998 +A2: 2003 Information technology equipment - Radio disturbance
I, the undersigned, hereby declare that the equipment specified above conforms to the above Directive and Standards.
Manufacturer
Signature:
Control, and Laboratory Use, Part 1: General Requirements.
Use - EMC Requirements – Part 1: General requirements
Safety of laser products – Part 1: Equipment classification,
requirements, and user’s guide
characteristics - Limits and methods of measurement
2004/108/EC - The EMC Directive
And their amendments
Canada, G1M 2K2
PMD Analyzer
Full Name: Stephen Bull, E. Eng
Position: Vice-President Research and
Address: 400 Godin Avenue, Quebec (Quebec),
Date: January 09, 2009
Development
Canada, G1M 2K2
Polarization Mode Dispersion Analyzer vii
1 Introducing the FTB-5500B
Polarization Mode Dispersion
Analyzer
Main Features
Polarization mode dispersion (PMD) is the dispersion of light propagating
along a fiber or through a device due to the birefringence property of the
material. This dispersion causes a delay between two principal states of
polarization
The FTB-5500B Polarization Mode Dispersion Analyzer takes full advantage
of the IEC- and TIA-approved interferometric method to offer a fast and
field-proof unit that can handle almost any situation. This unit, used with
the FLS-5800 CD/PMD Analyzer Source, features the best dynamic range on
the market to measure links longer than 200 km. The Polarization Mode
Dispersion Analyzer covers the O+C+L bandwidth.
The FTB-5500B Polarization Mode Dispersion Analyzer offers a dynamic
range higher than 50 dB for long-haul applications; multiple-measurement
capability for long-term monitoring; and an estimated second-order PMD
for DWDM system fiber certifications.
Polarization Mode Dispersion Analyzer 1
Introducing the FTB-5500B Polarization Mode Dispersion Analyzer
Typica l A p p l i cations
The FTB-5500B Polarization Mode Dispersion Analyzer is a complete PMD
analyzer system. It measures PMD using the internationally recognized
interferometric method. The Polarization Mode Dispersion Analyzer
averages PMD over the complete source wavelength range without any
filtering, leaving all the source power for PMD measurement. The full
dynamic range remains available to test long fiber spans. It can withstand
small vibrations thanks to its fast measurement time and does not require
any special environmental setup to perform reliable measurements.
PMD
Handle
FTB-5500B
Port
Typical Applications
The Polarization Mode Dispersion Analyzer can also analyze a signal
transmitted through erbium-doped fiber amplifiers (EDFAs) providing a
total PMD value for the entire link.
2 FTB-5500B
Introducing the FTB-5500B Polarization Mode Dispersion Analyzer
Basic Polarization Mode Dispersion Theory
Basic Polarization Mode Dispersion Theory
The dispersion phenomenon is described as a number of
non-intensity-dependant physical occurrences resulting directly in signal
loss (pulse spreading or time jitter in a digital system; distortion in an
analog system). PMD is an important type of signal dispersion. As
unrepeated link distances are increased and transmission rates pushed
upwards, PMD can significantly reduce system performance.
To better understand the impact of PMD, consider the example of a pulse
passing through a wave plate. Upon entering the wave plate, the pulse is
decomposed into polarization components aligned with each of the two
birefringent axes of the plate (known as the fast and slow axes). The
components propagating independently through the wave plate at different
group velocities will recombine at the end of the wave plate as a
superposition of two pulses split in time.
The delay between those pulses is designated as the differential group
delay (DGD) and is written as δτ. For a Gaussian, unchirped input pulse
of rms width σ0, the rms width at the output is given by
2
2
σ
= σ
+ r0 (1 − r0)•δτ
0
where r0 is the fraction of the input-pulse energy launched into one of the
birefringence axes.
2
Worst-case spreading occurs when the signal is perfectly split in two
(r0 = 1/2), while no spreading occurs if the input state of polarization
(SOP) of the launched signal is aligned with one of the birefringence axes.
To generalize this example, consider a long, weakly birefringent
telecommunications fiber as a concatenation of many, randomly
orientated birefringent wave plates. Each interface between two wave
plates redistributes the optical energy along both axes of the subsequent
wave plate. This transfer of energy is called mode coupling.
Polarization Mode Dispersion Analyzer 3
Introducing the FTB-5500B Polarization Mode Dispersion Analyzer
Basic Polarization Mode Dispersion Theory
In a long fiber, numerous mode-coupling events occur along the fiber
length, so that light emerging from the output end is the superposition of a
number of pulses with different delays. Nonetheless, it turns out that for
any given optical frequency,
principal states of polarization (PSPs) such that a light pulse with the same
input SOP as the input PSP, undergoes no spreading. For a single wave
plate, the PSPs are the two birefringent axes, whereas for a concatenation
of wave plates, neither the input nor the output PSPs correspond to the
alignment of the birefringent axes anywhere.
Contrary to the case of a wave plate, the DGD and PSPs of a long fiber are
dependent on wavelength and fluctuate in time as a result of
environmental variations such as temperature, external mechanical
constraints, etc. Their behavior is random, both as a function of wavelength
at a given time and as a function of time at a given wavelength. Fortunately,
this behavior can be characterized statistically. It can be demonstrated that
the probability density function of δτ is Maxwellian and, by definition, PMD
is its rms value, that is:
ω, one can always find two orthogonal input
PMD =
Note: PMD is sometimes defined as the mean value of the DGD, which for a
Maxwellian distribution yields a value 17% lower than the rms definition.
If the average is calculated over
averaging window is sufficiently large (
4 FTB-5500B
√<DGD2>
ω, PMD is stable in time, provided that the
Δωδτ >> 1).
Introducing the FTB-5500B Polarization Mode Dispersion Analyzer
Basic Polarization Mode Dispersion Theory
It is essential to keep in mind that DGD fluctuates in time and can be either
smaller or larger than its rms value or PMD. This results in a statistical
probability that a pulse (information bit) is broadened, and leads to the
eventual impaired ability of the receiver to efficiently decode the
information. This adverse PMD effect makes it a critical phenomenon in
limiting transmission of high-bit-rate information.
In the case of PMD in a long fiber, there is a specific state called input PSP.
In this state, when the input SOP of the signal is aligned with one of its
axes, it will propagate through the fiber without any spreading or distortion
of the signal. This phenomenon is defined as this specific input SOP such
that the output SOP is independent of optical frequency. Again, the worst
case occurs when the signal is equally split between both input PSPs.
For long telecom fibers with random coupling of energy between modes
(that is L >> h where h is the coupling length), PMD grows as the square
root of the distance, whereas PMD of strong HiBi fiber (negligible mode
coupling) is directly proportional to the distance. Therefore, the PMD
coefficient for negligible mode coupling is expressed as ps/km, while
the PMD coefficient for random mode coupling is defined as ps/km
1/2
.
Polarization Mode Dispersion Analyzer 5
Introducing the FTB-5500B Polarization Mode Dispersion Analyzer
Conventions
Conventions
Before using the product described in this manual, you should understand
the following conventions:
WARNING
Indicates a potentially hazardous situation which, if not avoided,
could result in death or serious injury. Do not proceed unless you
understand and meet the required conditions.
CAUTION
Indicates a potentially hazardous situation which, if not avoided,
may result in minor or moderate injury. Do not proceed unless you
understand and meet the required conditions.
CAUTION
Indicates a potentially hazardous situation which, if not avoided,
may result in component damage. Do not proceed unless you
understand and meet the required conditions.
IMPORTANT
Refers to information about this product you should not overlook.
6 FTB-5500B
2 Safety Information
WARNING
Do not install or terminate fibers while a light source is active.
Never look directly into a live fiber and ensure that your eyes are
protected at all times.
WARNING
Use of controls, adjustments and procedures for operation and
maintenance other than those specified herein may result in
hazardous radiation exposure or impair the protection provided by
this unit.
Your instrument is a Class 1 laser product in compliance with standards
IEC60825-1: 2001, 2007 and 21CFR1040.10. Laser radiation may be
encountered at the output port.
The following label indicates that a product contains a Class 1 source:
CLASS 1
LASER PRODUCT
Note: Label shown for information purposes only. It is not affixed to your product.
Polarization Mode Dispersion Analyzer 7
3 Getting Started with Your
Polarization Mode Dispersion
Analyzer
Inserting and Removing Test Modules
CAUTION
Never insert or remove a module while the FTB-500 is turned on.
This will result in immediate and irreparable damage to both the
module and unit.
WARNING
When the laser safety LED ( ) is flashing on the FTB-500, at least
one of your modules is emitting an optical signal. Please check all
modules, as it might not be the one you are currently using.
To insert a module into the FTB-500:
1. Exit ToolBox and turn off your unit.
2. Position the FTB-500 so that its right panel is facing you.
Polarization Mode Dispersion Analyzer 9
Getting Started with Your Polarization Mode Dispersion Analyzer
Inserting and Removing Test Modules
3. Take the module and place it so that the connector pins are at the
back, as explained and shown below.
Identification sticker must be facing up and connector pins at the right
of the retaining screw hole.
FTB-500 right panel
4. Insert the protruding edges of the module into the grooves of the
5. Push the module all the way to the back of the slot, until the retaining
6. Place the FTB-500 so that its left panel is facing you.
Retaining screw
hole at the
back
Identification sticker
facing up
receptacle’s module slot.
screw makes contact with the receptacle casing.
Connector
pins at the
back
Protruding
edges on top
10 FTB-5500B
Getting Started with Your Polarization Mode Dispersion Analyzer
Inserting and Removing Test Modules
7. While applying slight pressure to the module, turn the retaining screw
clockwise until it is tightened.
This will secure the module into its “seated” position.
Turn retaining screw knob
clockwise
FTB-500 left panel
When you turn on the unit, the startup sequence will automatically detect
the module.
Polarization Mode Dispersion Analyzer 11
Getting Started with Your Polarization Mode Dispersion Analyzer
Inserting and Removing Test Modules
To remove a module from the FTB-500:
1. Exit ToolBox and turn off your unit.
2. Position the FTB-500 so that the left panel is facing you.
3. Turn the retaining screw counterclockwise until it stops.
The module will be slowly released from the slot.
Turn retaining screw knob(s)
counterclockwise
FTB-500 left panel
4. Place the FTB-500 so that the right panel is facing you.
12 FTB-5500B
Getting Started with Your Polarization Mode Dispersion Analyzer
Inserting and Removing Test Modules
5. Hold the module by its sides or by the handle (NOT by the connector)
and pull it out.
Polarization Mode Dispersion Analyzer 13
Getting Started with Your Polarization Mode Dispersion Analyzer
Starting the Polarization Mode Dispersion Analyzer Application
Starting the Polarization Mode Dispersion
Analyzer Application
Your FTB-5500B Polarization Mode Dispersion Analyzer module can be
configured and controlled from its dedicated ToolBox application.
Note: For details about ToolBox, refer to the FTB-500 user guide.
To start the application:
1. From the main window, select the module to use.
It will turn blue to indicate that it is highlighted.
2. Click the corresponding button in the Module Applications box.
14 FTB-5500B
Getting Started with Your Polarization Mode Dispersion Analyzer
Starting the Polarization Mode Dispersion Analyzer Application
The main window (shown below) contains all the commands required to
control the Polarization Mode Dispersion Analyzer:
Data
display
Zoom controls
Power level
indicator
Measurement
selector
Export controls
Threshold indicator
specifies if measurement
exceeded value or not
Title bar
Start/Stop
button
Function
buttons
Status
bar
Polarization Mode Dispersion Analyzer 15
Getting Started with Your Polarization Mode Dispersion Analyzer
Starting the Polarization Mode Dispersion Analyzer Application
Data Display
The data display section shows both a graph and a table of results. The
graph presents a signal intensity trace as a function of delay. The table
presents information and results related to the measurement specified in
the measurement selector.
Signal
intensity in
percentage
PMD time
delay in
picoseconds
Measurement
selector
16 FTB-5500B
Getting Started with Your Polarization Mode Dispersion Analyzer
Exiting the Application
Status Bar
The status bar, located at the bottom of the main window, identifies the
operational status of the FTB-5500B Polarization Mode Dispersion Analyzer.
Control mode
Local: Module controlled locally only.
Remote: Module controlled remotely, but local
commands can also be used (some products only).
Lockout: Module controlled remotely only.
Current date and time
Battery indicator
For more information about automating or remotely controlling the
FTB-5500B Polarization Mode Dispersion Analyzer, refer to your platform
user guide.
Exiting the Application
Closing any application that is not currently being used helps freeing
system memory.
To close the application from the main window:
Click in the top right corner of the main window.
OR
Click the Exit button located at the bottom of the function bar.
Polarization Mode Dispersion Analyzer 17
4 Setting Up the Polarization
Mode Dispersion Analyzer
The many features of the Polarization Mode Dispersion Analyzer are
controlled by the Windows-compatible ToolBox software. Please refer to
the FTB-500 user guide for information regarding the FTB-500.
Defining the Automatic Fiber Name Format
Each time you make a new acquisition, the fiber name changes
automatically according to a pattern you will have previously defined. This
name corresponds to the concatenation of a static part (prefix) and a
variable part that will be incremented.
Note: The fiber name can be modified later with the measurement information
utility. For more information, see Documenting Results on page 58.
To define the fiber name format:
1. From the main window, click the Parameters tab.
2. From the Fiber Auto Naming panel, set the various parameters
according to your needs.
Fiber identification number. Will change
according to the specified increment value.
Number of digits composing the fiber
identification number.
Value that will be added the fiber identification
Polarization Mode Dispersion Analyzer 19
Displayed just before the
number in the fiber name.
number to build the next fiber name.
Setting Up the Polarization Mode Dispersion Analyzer
Customizing PMD Value and Coefficient Thresholds
Customizing PMD Value and Coefficient
Thresholds
The Polarization Mode Dispersion Analyzer allows you to specify PMD and
coefficient values that will be used to determine whether the results are as
expected or if they exceed the specified limits.
Note: You cannot modify or delete the predefined thresholds provided with your
Polarization Mode Dispersion Analyzer.
To add a new threshold:
1. From the button bar, click Setup.
20 FTB-5500B
2. From the PMD Value panel, click Add.
Current
threshold values
(preceded by
bullets)
Setting Up the Polarization Mode Dispersion Analyzer
Customizing PMD Value and Coefficient Thresholds
OR
From the PMD Coefficient panel, click Add.
3. From the PMD Value list, select the threshold that has just been added.
OR
From the PMD Coefficient list, select the threshold that has just been
added.
4. Fill in the Name and Value boxes according to your needs.
Note: If you want the Polarization Mode Dispersion Analyzer to use this new
value next time you will make an acquisition, you will have to set it from
the main window Parameters tab (see Setting Acquisition Parameters on
page 24).
Polarization Mode Dispersion Analyzer 21
Setting Up the Polarization Mode Dispersion Analyzer
Customizing PMD Value and Coefficient Thresholds
To m o d i fy a n e xisting threshold:
1. From the button bar, click Setup.
2. From the PMD Value list, select the threshold to be modified.
OR
From the PMD Coefficient list, select the threshold to be modified.
3. Modify the contents of the Name and Valu e boxes according to your
needs.
Note: If you want the Polarization Mode Dispersion Analyzer to use this new
value next time you will make an acquisition, you will have to set it from
the main window Parameters tab (see Setting Acquisition Parameters on
page 24).
22 FTB-5500B
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