EXFO FTB-5800 User Manual
NETWORK TESTING
CHROMATIC DISPERSION
ANALYZER
FTB-5800 for FTB-400
USER GUIDE
Copyright © 2002–2007 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 Chromatic Dispersion Analyzer is protected by US patent 6,429,929 and
foreign equivalents; EXFO’s Universal Interface is protected by US patent
6,612,750.
Version number 1.3.3
ii FTB-5800
Contents
Contents
Certification Information ........................................................................................................v
1 Introducing the FTB-5800 Chromatic Dispersion Analyzer ........................ 1
Main Features .........................................................................................................................1
Basic Theory ............................................................................................................................3
Typical Applications ................................................................................................................3
Conventions ............................................................................................................................4
2 Getting Started with Your Chromatic Dispersion Analyzer ....................... 5
Inserting and Removing Test Modules ...................................................................................5
Starting the Chromatic Dispersion Analyzer Application .......................................................10
Exiting the Application .........................................................................................................12
3 Setting Up Your Chromatic Dispersion Analyzer ...................................... 13
Setting the Wavelength Range .............................................................................................13
Setting the Wavelength Step ................................................................................................14
Setting the Averaging Time ..................................................................................................16
Specifying the Fiber Under Test .............................................................................................17
Defining the Automatic Fiber Name Format .........................................................................20
4 Operating Your Chromatic Dispersion Analyzer ....................................... 23
Installing the EXFO Universal Interface (EUI) .........................................................................23
Cleaning and Connecting Optical Fibers ...............................................................................24
Selecting the Source Type .....................................................................................................26
Verifying the Intensity of the Source .....................................................................................27
Performing Reference Measurements ...................................................................................28
Applying a Chromatic Dispersion Reference .........................................................................33
Creating a File .......................................................................................................................34
Measuring Chromatic Dispersion ..........................................................................................35
Saving Your Results ...............................................................................................................38
5 Managing Results ....................................................................................... 41
Recalling a Saved File ............................................................................................................42
Analyzing Results from the Results Graph ............................................................................43
Analyzing Results from the Results Table ..............................................................................52
Keeping Track of Acquisitions ...............................................................................................54
Establishing Thresholds ........................................................................................................56
Documenting Results ............................................................................................................59
Exporting Results and Graphs to Clipboard ..........................................................................61
Printing Results .....................................................................................................................62
Chromatic Dispersion Analyzer iii
Contents
6 Exporting CD Analyzer Files with the File Export Tool .............................65
Starting and Exiting the File Export Tool ...............................................................................65
Setting Export Parameters ....................................................................................................67
Exporting Chromatic Dispersion Files ....................................................................................69
7 Maintenance ................................................................................................71
Cleaning EUI Connectors ......................................................................................................72
Cleaning Detector Ports ........................................................................................................74
Recalibrating the Unit ...........................................................................................................75
Recycling and Disposal (Applies to European Union Only) ....................................................76
8 Troubleshooting ..........................................................................................77
Solving Common Problems ...................................................................................................77
Viewing Online Documentation ............................................................................................79
Finding Information on the EXFO Web Site ..........................................................................79
Contacting the Technical Support Group ..............................................................................80
Transportation ......................................................................................................................81
9 Warranty ......................................................................................................83
General Information .............................................................................................................83
Liability .................................................................................................................................84
Exclusions .............................................................................................................................84
Certification ..........................................................................................................................84
Service and Repairs ...............................................................................................................85
EXFO Service Centers Worldwide ..........................................................................................86
A Technical Specifications ..............................................................................87
B Measuring Chromatic Dispersion: Theory .................................................89
Method Behind the Chromatic Dispersion Analyzer ..............................................................89
Using Data Fits to Obtain Dispersion ....................................................................................90
Helping You Manage Chromatic Dispersion ..........................................................................92
Index .................................................................................................................93
iv FTB-5800
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.
Chromatic Dispersion Analyzer v
Certification Information
Application of Council Directive(s):
73/23/EEC - The Low Voltage Directive
89/336/EEC - The EMC Directive
Manufacturer’s Name:
EXFO ELECTRO-OPTICAL ENG.
Manufacturer’s Address:
400 Godin Avenue
Quebec, Quebec
Canada G1M 2K2
(418) 683-0211
Equipment Type/Environment:
Industrial Scientific Equipment
Trade Name/Model No.:
FTB-5800 Chromatic Dispersion Analyzer
Year of Conformity Assessment:
2002
Standard(s) to which Conformity is Declared:
EN 61326: 1997/ A2:
2001
Electrical Equipment for Measurement, Control and Laboratory
Use - EMC Requirements
EN 55022: 1998/ A1:
2000
Limits and methods of measurement of radio disturbance characteristics of
information technology equipment
I, the undersigned, hereby declare that the equipment specified above conforms to the above Directive and Standards.
Manufacturer
Signature:
Full Name:
Stephen Bull, E. Eng
Position:
Vice-President Research and
Development
Address:
400 Godin Avenue Quebec, Quebec,
Canada
Date:
February 25,2002
DECLARATION OF CONFORMITY
vi FTB-5800
1 Introducing the FTB-5800
FTB-5800
CHROMATIC DISPERSON ANALYZER
LOW POWER
HIGH POWER/REF
High-power/
reference
port
Low-power
port
Chromatic Dispersion
Analyzer
In today’s advanced optical network, chromatic dispersion management
has become an important issue. Present-day networks must deal with high
data rates, high channel counts and long distances between
optical-electrical-optical regenerators.
Main Features
The FTB-5800 Chromatic Dispersion Analyzer is a reliable solution to
chromatic dispersion management. It uses the phase-shift measurement
method to measure phase variations at fixed frequencies and combines
them relative group delays.
Fitting equations are then applied to the computed data to calculate
chromatic dispersion. This method allows for more accurate and precise
results in the C and L bands.
Chromatic Dispersion Analyzer 1
Introducing the FTB-5800 Chromatic Dispersion Analyzer
Main Features
The architecture of the FTB-5800 Chromatic Dispersion Analyzer places the
wavelength selector in the receiver, which avoids the necessity for any
communication between the receiver and the source. This allows you to
take measurements even though the source is kilometers away, without
interfering with the accuracy of results.
The FTB-5800 Chromatic Dispersion Analyzer is offered as a compact,
portable and field-ready module used in the FTB-400 Universal Test System
and combined with the FLS-5800 for optimal test results. The FTB-5800
Chromatic Dispersion Analyzer comes with user-friendly software, which
allows you to perform your acquisition, and then view, analyze and save
your results easily.
2 FTB-5800
Introducing the FTB-5800 Chromatic Dispersion Analyzer
Basic Theory
Basic Theory
Chromatic dispersion is the natural broadening of light pulses as they travel
through optical fiber. The propagation characteristics of each wavelength
depend on the refractive index of the medium and on the non-linearity of
the propagation constant. These affect the travel time of each wavelength
through the fiber medium. An initially narrow pulse is widened as a result
of this, and as the pulses spread, they begin to overlap, causing the bit error
rate to increase.
High data rates mean pulses are closely spaced in time and have less room
to spread before they overlap. High channel count increases the difficulty
in correcting dispersion since each channel experiences different levels of
dispersion.
Long distances between regenerators require that dispersion be managed
very precisely because the effects accumulate over distance. As link length
and bit rate increase, the effects of chromatic dispersion also increase.
Chromatic dispersion is therefore one of the main factors limiting data
transfer for modern optical networks.
Typical Applications
Getting precise chromatic dispersion parameters helps you choose the
right dispersion-compensated fiber or material in order to reverse the
dispersion and dispersion slope before data are interpreted by the receiver.
Chromatic Dispersion Analyzer 3
Introducing the FTB-5800 Chromatic 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.
4 FTB-5800
2 Getting Started with Your
Chromatic Dispersion
Analyzer
IMPORTANT
The power consumption of the module is relatively high. Therefore,
it is not recommended to use it with battery or to activate other
power consuming modules at the same time on the platform.
Inserting and Removing Test Modules
CAUTION
Never insert or remove a module while the FTB-400 Universal Test
System 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-400, 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-400 Universal Test System:
1. Exit ToolBox and turn off your unit.
2. Position the FTB-400 so that its right panel is facing you.
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 down and connector pins at the left of the retaining screw hole.
CAUTION
Inserting a module upside down could result in permanent damage
to the module, as the connector pins might be bent.
Chromatic Dispersion Analyzer 5
Getting Started with Your Chromatic Dispersion Analyzer
FTB-400 right panel
(7-slot receptacle
shown)
Protruding
edges on top
Retaining screw
hole at the
back
Connector
pins at the
back
Identification sticker
facing down
Inserting and Removing Test Modules
4. Insert the protruding edges of the module into the grooves of the
receptacle’s module slot.
6 FTB-5800
5. Push the module all the way to the back of the slot, until the retaining
screw makes contact with the receptacle casing.
6. Place the FTB-400 so that its left panel is facing you.
Getting Started with Your Chromatic Dispersion Analyzer
Turn retaining screw knob
clockwise
FTB-400 left panel
(7-slot unit shown)
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.
When you turn on the unit, the startup sequence will automatically detect
the module.
Chromatic Dispersion Analyzer 7
Getting Started with Your Chromatic Dispersion Analyzer
Turn retaining screw knob(s)
counterclockwise
FTB-400 left panel
(7-slot unit shown)
Inserting and Removing Test Modules
To remove a module from the FTB-400 Universal Test System:
1. Exit ToolBox and turn off your unit.
2. Position the FTB-400 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.
4. Place the FTB-400 so that the right panel is facing you.
5. Hold the module by its sides or by the handle (NOT by the connector)
and pull it out.
8 FTB-5800
Getting Started with Your Chromatic Dispersion Analyzer
Inserting and Removing Test Modules
CAUTION
Pulling out a module by a connector could seriously damage both
the module and connector. Always pull out a module by its casing.
6. Cover empty slots with the supplied protective covers.
CAUTION
Failure to reinstall protective covers over empty slots will result in
ventilation problems.
Chromatic Dispersion Analyzer 9
Getting Started with Your Chromatic Dispersion Analyzer
Starting the Chromatic Dispersion Analyzer Application
Starting the Chromatic Dispersion Analyzer
Application
Your FTB-5800 Chromatic Dispersion Analyzer module may be fully
configured and controlled from its dedicated ToolBox application.
Note: For details about ToolBox, refer to the FTB-400 Universal Test System user
guide.
To start the Chromatic Dispersion Analyzer application:
1. From the Current Modules function tab, select the row corresponding
to the module you wish to use. It will turn white to indicate that it is
highlighted.
2. Press the corresponding button in the Online Applications box.
10 FTB-5800
Getting Started with Your Chromatic Dispersion Analyzer
Ta bs
RGD
parameters
panel
Fiber
Information
panel
Intensity
meters
Status bar
Button bar
Source type
Slot number in which module is inserted
(0 identifies first slot)
Unit housing the module
(1 identifies FTB-400)
[1– 1]
Starting the Chromatic Dispersion Analyzer Application
The main window (shown below) contains all the commands required to
control the Chromatic Dispersion Analyzer:
Title Bar
The title bar is located at the top of the main window. It displays the
module name and its position in the FTB-400 Universal Test System. The
module position is identified as follows:
Note: On some 7-slot backplanes, slots are marked with a letter from A to G.
Chromatic Dispersion Analyzer 11
Getting Started with Your Chromatic Dispersion Analyzer
Current date and timeModule/unit status
Local: Module controlled locally only.
Remote: Module controlled remotely, but local
commands can also be used (some products only).
Lockout: Module controlled remotely only.
Battery indicator
Control mode
Exiting the Application
Status Bar
The status bar, located at the bottom of the main window, identifies the
current operational status of the FTB-5800 Chromatic Dispersion Analyzer.
For more information about automating or remotely controlling the
FTB-5800 Chromatic Dispersion Analyzer, refer to the FTB-400 Universal
Test System user guide.
Exiting the Application
Closing any application that is not currently being used is a good way to
free up system memory.
To close the application from the main window:
³ Click on (in the top right corner of the main window).
³ Click on the Exit button located at the bottom of the function bar.
12 FTB-5800
3 Setting Up Your Chromatic
Dispersion Analyzer
The parameters you set will be kept in memory after turning off the
FTB-400 Universal Test System.
Setting the Wavelength Range
You can set the wavelength range within which you want to perform your
acquisitions. You can work with predefined bands (C, L or C+L) or set the
wavelength range by using the custom option. This option could be useful
to perform acquisitions in a specific area of a band or between two bands.
IMPORTANT
Make sure you connect the source corresponding to the wavelength
range you select at the other end of the link.
To select a predefined wavelength range:
On the Parameters tab, use the Range dial.
To set the wavelength range using the custom option:
1. On the Parameters tab, set the Range dial to Custom.
2. Enter your values in the From: and To : fields. The values you enter
must be between 1530 and 1625 nm, which are, respectively, the lower
limit of the C band and the upper limit of the L band.
Chromatic Dispersion Analyzer 13
Setting Up Your Chromatic Dispersion Analyzer
Setting the Wavelength Step
Setting the Wavelength Step
The wavelength step corresponds to the interval, in nanometers, at which
the system will take RGD measurements within the selected wavelength
range. You can either choose one of the preprogrammed step or specify
the desired value with the custom option.
Note: The smaller the step you choose, the higher the accuracy of your
measurement will be and the longer the acquisition will take. For unknown
fiber type or amplified links, EXFO strongly recommends selecting the
smallest step possible.
To select a predefined wavelength step:
On the Parameters tab, use the Step dial.
14 FTB-5800
Setting Up Your Chromatic Dispersion Analyzer
λmax λmin–
λΔ
Setting the Wavelength Step
To set the wavelength step using the custom option:
1. In the Parameters tab, set the Step dial to Custom.
2. Enter the desired value in the Step box. The value must be between
0.1 nm and the wavelength range you chose previously.
Moreover, the final measurement point, may not correspond to the
upper limit of the wavelength range if the wavelength span
is not an integer value of
A warning message will indicate if your step is too small or too large.
Chromatic Dispersion Analyzer 15
Setting Up Your Chromatic Dispersion Analyzer
Setting the Averaging Time
Setting the Averaging Time
The averaging time is the time the system spends on one specific point or
wavelength. You can either choose one of the preprogrammed values or
specify the desired averaging time with the custom option.
Note: The stronger the signal, the faster a signal-to-noise ratio (SNR) will be
reached. If your signal is weak, increase the averaging time in order to
increase the accuracy of your results. Beyond a certain time limit, however,
the accuracy you gain will be insignificant.
To select a predefined averaging time:
On the Parameters tab, use the Averaging Time dial.
To set averaging time using custom option:
1. In the Parameters tab, set the Averaging Time dial to Custom.
2. Enter a value between 1.0 s and 60.0 s in the Avg Time box. The system
will warn you if the value exceeds those limits.
Note: The averaging time displayed on the screen does not take stabilizing time
into account. The Estimated Acq. Time field will give you an idea of the
overall time your acquisition will take, including the time needed for the
system to stabilize, as this time can vary.
16 FTB-5800
Setting Up Your Chromatic Dispersion Analyzer
Specifying the Fiber Under Test
Specifying the Fiber Under Test
Before making an acquisition, you must also enter information on the fiber
you are going to test. This information includes the fiber type, the data fit
and the fiber length. You can also specify the distance units to be used.
Whether you know the fiber length or not will affect your results display.
³ Unknown fiber length: results will show the total dispersion.
³ Known fiber length: results will give out the dispersion per kilometer.
Note: The units you modify are only used when you specify the fiber length. On
the scales, as well as for calculation, the distance will always remain in
kilometers.
Chromatic Dispersion Analyzer 17
Setting Up Your Chromatic Dispersion Analyzer
Specifying the Fiber Under Test
To specify the fiber under test:
In the Parameters tab, undr Fiber Information, set the fiber parameters.
³ In the Fiber Type list, select the appropriate value.
Note: If you do not know the fiber type, select “Unknown Fiber Type”. If your fiber
is made of more than one type of fiber, either enter the dominant fiber type
or select “Unknown Fiber Type”.
³ The application will designate a default fit according to the fiber type; it
will be marked by an asterisk (*) to indicate that it is a default value. If
necessary, in the RGD Data Fit list, select the desired data fit.
Note: The RGD data fit you select here will be applied to the relative group delay
for the next acquisition. However, once in the Results Graph tab, it is
possible to interpret your results by selecting another fit.
³ If you know the fiber length, select the Known Fiber Length box and
enter the appropriate fiber length in the corresponding box. By default,
the value is in kilometers.
18 FTB-5800
Setting Up Your Chromatic Dispersion Analyzer
Specifying the Fiber Under Test
To modify the distance units:
1. On the button bar, click the Setup button, to access the Application
Setup dialog box.
2. Under Distance Unit, select the desired units.
3. Click OK to confirm the new settings or Cancel to discard them.
Chromatic Dispersion Analyzer 19
Setting Up Your Chromatic Dispersion Analyzer
Defining the Automatic Fiber Name Format
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 is made of a static part (prefix) and a variable part that will be
incremented.
The increment can be positive, negative or null (zero). Entering zero gives
you the opportunity to use the same acquisition fiber name.
Note: The number you can enter will depend on the number of digits you have
specified. For example, if you set two digits, the maximum you can enter
is 99. Once the system reaches 99, it will step back to 00. If the selected
increment is negative, when the system reaches 00, it will step back to 99.
If you do not enter any prefix or number, the fiber will be identified with
one number only.
Note: You can modify the fiber name later, when the acquisitions are complete.
For more information, see Documenting Results on page 59.
Note: You cannot define the automatic fiber name format in offline mode.
20 FTB-5800
Setting Up Your Chromatic Dispersion Analyzer
Number of digits composing the
fiber identification number
Value that will be added to the fiber identification
number to build the next fiber name
Static part Variable part (incremented)
Defining the Automatic Fiber Name Format
To define the fiber name format:
1. On the button bar, click Setup.
2. Under Autonaming, set the various parameters according to your
needs.
Chromatic Dispersion Analyzer 21
4 Operating Your Chromatic
Bare metal
(or blue border)
indicates UPC
option
Green border
indicates APC
option
2 3 4
Dispersion Analyzer
Installing the EXFO Universal Interface (EUI)
The EUI fixed baseplate is available for connectors with angled (APC) or
non-angled (UPC) polishing.A green border around the baseplate indicates
that it is for APC-type connectors.
To install an EUI connector adapter onto the EUI baseplate:
1. Hold the EUI connector adapter so the dust cap opens downwards.
2. Close the dust cap in order to hold the connector adapter more firmly.
3. Insert the connector adapter into the baseplate.
4. While pushing firmly, turn the connector adapter clockwise on the
baseplate to lock it in place.
Chromatic Dispersion Analyzer 23
Operating Your Chromatic Dispersion Analyzer
Cleaning and Connecting Optical Fibers
Cleaning and Connecting Optical Fibers
IMPORTANT
To ensure maximum power and to avoid erroneous readings:
³ Always clean fiber ends as explained below before inserting
them into the port. EXFO is not responsible for damage or
errors caused by bad fiber cleaning or handling.
³ Ensure that your patchcord has appropriate connectors. Joining
mismatched connectors will damage the ferrules.
To connect the fiber-optic cable to the port:
1. Clean the fiber ends as follows:
1a. Gently wipe the fiber end with a lint-free swab dipped in isopropyl
alcohol.
1b. Use compressed air to dry completely.
1c. Visually inspect the fiber end to ensure its cleanliness.
2. Carefully align the connector and port to prevent the fiber end from
touching the outside of the port or rubbing against other surfaces.
If your connector features a key, ensure that it is fully fitted into the
port’s corresponding notch.
3. Push the connector in so that the fiber-optic cable is firmly in place,
thus ensuring adequate contact.
If your connector features a screwsleeve, tighten the connector
enough to firmly maintain the fiber in place. Do not overtighten, as this
will damage the fiber and the port.
Note: If your fiber-optic cable is not properly aligned and/or connected, you will
notice heavy loss and reflection.
24 FTB-5800
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