Agilent 8509B Users Guide

User's/Reference Guide

HP 8509A/B LightwavePolarization

Analyzer

ABCDE

08509-90016

No.

Part

HP

Printed

in

USA

October

Supersedes:

1994

08509-90003

Notice.

The information contained in this document is sub ject to change

without notice.

Hewlett-Packard makes no warrantyofany kind with regard to this

material, including but not limited to, the implied warranties of

merchantability and tness for a particular purpose. Hewlett-Packard

shall not be liable for errors contained herein or for incidental

or consequential damages in connection with the furnishing,

performance, or use of this material.

Microsoft, MS, MS-DOS, and the Microsoft logo are registered

trademarks, and Windows is a trademark, of Microsoft Corporation.

c



All

Cop

Righ

yrigh

ts

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without prior

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ermission

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1992,

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prohibited,

is

CA

a

,

y

Santa

Rosa,

1994

or

except

95403,

translation

allo

as

USA

ed

w

Certification

Hewlett-Packard Company certies that this pro duct met its

published sp ecications at the time of shipment from the factory.

Hewlett-Packard further certies that its calibration measurements

are traceable to the United States National Institute of Standards

and Technology, to the extent allowed by the Institute's calibration

facility, and to the calibration facilities of other International

Standards Organization members.

Regulatory Information

Warranty

Chapter 9 contains regulatory information.

This Hewlett-Packard instrument product is warranted against

defects in material and workmanship for a perio d of one year from

date of shipment. During the warranty perio d, Hewlett-Packard

Company will, at its option, either repair or replace products which

b

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Limitation of Warranty

The foregoing warranty shall not apply to defects resulting from

improper or inadequate maintenance byBuyer, Buyer-supplied

software or interfacing, unauthorized modication or misuse,

the

eration

op

pro

duct,

outside

or

NO OTHER W

of

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preparation

site

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ARRANTY IS EXPRESSED OR

vironmental

en

the

HEWLETT-PACKARD SPECIFICALL

IMPLIED W

FITNESS F

ARRANTIES OF MER

OR A P

ARTICULAR PURPOSE.

CHANTABILITY

ecications

sp

tenance.

main

Y DISCLAIMS THE

for

IMPLIED.

AND

Exclusive Remedies

THE REMEDIES PROVIDED HEREIN ARE BUYER'S SOLE

CKARD

AMA

D

A

GES,

SPECIAL,

WHETHER

AND EX

NOT

CLUSIVE

LIABLE

BE

INCIDENT

AL,

REMEDIES.

ANY

OR

F

CONSEQUENTIAL

OR

HEWLETT-P

DIRECT,

INDIRECT,

SHALL

iii

BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL

THEORY.

Assistance

Safety Notes

Caution

W

arning

Product maintenance agreements and other customer assistance

agreements are available for Hew lett-Packardproducts.

For any assistance, contact your nearest Hewlett-Packard Sales and

ServiceOce.

The following safety notes are used throughout this manual.

Familiarize yourself with each of the notes and its meaning b efore

operating this instrument.

cedure that,

pro

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not

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\CE" The CE mark is a registered trademark of the European

Community. (If accompanied byayear, it is when the design was

proven.)

Industrial

an

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1

This

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\ISM1-A"

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\CSA" The CSA mark is a registered trademark of

Scien

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Medical

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tic

Standards Asso ciation.

iv

General Safety Considerations

Warning

Caution

This is a Safety Class I product (provided with a protective earthing

ground incorporated in the power cord). The mains plug shall only be

inserted in a socket outlet provided with a protective earth contact.

Any interruption of the protective conductor, inside or outside the

instrument, is likely to make the instrument dangerous. Intentional

interruption is prohibited.

No operator serviceable parts inside. Refer servicing to qualified

personnel. To prevent electrical shock, do not removecovers.

Before switching on this instrument, make sure that the line voltage

selector switch is set to the voltage of the power supply and the

correct fuse is installed.

v

Contents

1. Getting Started

Description of the Instrument . . . . . . . . . . 1-1

Installation . . . . . . . . . . . . . . . . . . 1-1

About This Manual Set . . . . . . . . . . . . . 1-2

This guide uses the following conventions: . . . . 1-2

HP 8509A/B User's/Reference Guide Table of

Contents (this manual) . . . . . . . . . . . 1-3

The Main Menu . . . . . . . . . . . . . . . . 1-4

The Data Displays (Power, DOP, Ellipse and Poincare

Sphere) . . . . . . . . . . . . . . . . . . 1-5

.

y

Ellipse

unctions

F

Mark

a

Mark

a

Mark

Sphere

the

.

. .

.

er

oin

.

ers

. .

.

t

.

at

On

P

.

Curren

the

User-Sp

a

and O

.

Mark

a

on

olarization

.

. .

.

. .

.

ecied

.

er

.

P

Data

t

oin

P

.

Curren

or

Reference

.

oin

.

. 1-5

.

. 1-5

. .

.

t

. 1-7

.

t

.

t

oin

P

t

. .

.

. 1-10

. .

wer

Po

DOP

oincare

P

olarization

P

Mark

The

Setting

urning

T

Clearing

Cen

Tw

om and

Zo

Zoom

Displa

tering

or

o-

Display

Sphere

er

Marker

a

the

the Mark

Three-P

Rotate .

.

ToZoomIn . . . . . . . . . . . . . . . . 1-10

To Zoom Out . . . . . . . . . . . . . . . 1-10

The Zo om Factor Function . . . . . . . . . 1-10

Rotate . . . . . . . . . . . . . . . . . . . 1-11

To Rotate the Sphere . . . . . . . . . . . . 1-11

The

4

5

Home

4

Clea

r

4

ClearT

T

race

and

5

. . . . . . . . . . . . . . . . . . 1-11

race

Hold . . . . . .

45

and Cal

45

Source W

. . . . . .

. . . . . . . . . . . . . . . . .

avelength . . . . . . . . . . . . . . 1-12

Button

Hold

.

. .

.

. . . . . . . . . . . . . . 1-11

. 1-12

. . . . . . . . . . . . . . . 1-12

. .

.

Cal . . . . . . . . . . . . . . . . . . . . . 1-12

1-5

1-6

1-7

1-8

1-9

1-10

1-11

Contents-1

2. Making Measurements

Conventions . . . . . . . . . . . . . . . . . 2-1

PMD Measurement: Jones Matrix Eigenanalysis

Method . . . . . . . . . . . . . . . . . . 2-2

Basic Measurement. . . . . . . . . . . . . . . 2-3

Setting up the System . . . . . . . . . . . . 2-3

External Source Preparation . . . . . . . . . . 2-4

Making the Measurement . . . . . . . . . . . 2-8

Manipulating the Measurement Results . . . . . . 2-13

The Measurement Summary Bar . . . . . . . . 2-13

The Measurement Annotation Area . . . . . . . 2-14

Using The Cursor . . . . . . . . . . . . . . 2-15

Changing The MeasurementFormat . . . . . . 2-15

Changing The Graph's Y-Scale . . . . . . . . . 2-16

Displaying and Printing Data in Tabular Format . 2-16

Displaying Data in a Statistical Format . . . . . 2-17

The File menu . . . . . . . . . . . . . . . 2-19

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Add from Selected JME Window F2

N

Add

NN

N

Add

N

Load

N

Save Statistics...F6

N

Print Bitmap

N

Print

N

NN

Exit

The

The Help

The

ting

Prin

ving

Sa

Saving in Database Format . . . . . . . . . . 2-23

Specialized Measurement Metho ds . . . . . . . . 2-24

Performing a Cascade Measurement . . . . . . 2-24

Setting up the System . . . . . . . . . . . 2-24

Making

Using

PMD:JME Concepts

Polarization Mo de Dispersion

Polarization modes

General eects .

Mode coupling . . . . . . . . . . . . . . . 2-29

PMD units . . . . . . . . . . . . . . . . 2-30

Fiber PMD statistics . . . . . . . . . . . . . 2-30

Fitting

Enlarging

Source

Should

N

from

N

NN

from

N

NN

N

Statistics...F5

N

NN

N

NN

N

.

Edit

ormat

F

Annotation

the

our

y

the

oltage-T

V

a

Manually-T

a

the

ectral

sp

use

I

N

Database...F3

N

NN

N

Text

NN

N

NN

Data

.

u

men

Men

menu

PMD:JME

Measurement

Measuremen

uned

Maxw

sample

the

haracteristics

c

reference

the

N

NN

N

File...F4

N

NN

N

.

u

.

Area

Graph

Source

uned

. . . . . . . . .

. . . . . . . .

. . . . . . . . . . . . . . 2-29

ell curv

size

N

NN

N

NN

N

.

. .

.

. .

.

as T

t .

source

to

e

frame?

N

.

N

.

. .

.

. .

.

. .

.

ext .

.

. .

.

. . . . . . . . . 2-29

distribution

the

.

. . . . 2-19

.

. 2-19

.

. .

.

. 2-22

. .

.

. . . . . 2-29

.

. .

2-19

2-20

2-21

2-22

2-25

2-28

2-30

2-31

Contents-2

Cascade measurements . . . . . . . . . . . . 2-31

What is a cascade measurement? . . . . . . . 2-31

Typical applications . . . . . . . . . . . . 2-31

PMD Measurement: Wavelength-Scanning Method . 2-33

Basic Measurement. . . . . . . . . . . . . . . 2-34

Setting up the System . . . . . . . . . . . . 2-34

Making the Measurement . . . . . . . . . . . 2-35

Manipulating the Measurement Results . . . . . . 2-38

The Measurement Summary Bar . . . . . . . . 2-38

The Measurement Annotation Area . . . . . . . 2-39

Using The Cursor . . . . . . . . . . . . . . 2-39

Changing The MeasurementFormat . . . . . . 2-40

Displaying and Printing Data in Tabular Format . 2-41

Printing your Graph . . . . . . . . . . . . . 2-42

Saving your MeasurementasText . . . . . . . 2-43

Saving in Database Format . . . . . . . . . . 2-43

PMD:WS Concepts . . . . . . . . . . . . . . . 2-44

Polarization Mo de Dispersion . . . . . . . . . 2-44

2-44

.

for

range

.

size

Jones

.

. .

.

Matrix

. .

.

Jones

.

. .

.

. .

.

. .

.

test

t

onen

comp

or

er

b

.

. .

.

. .

.

PMD

er

b

of

Matrix

.

. .

t

Results

t

. . . . . . . . . . . . 2-61

.

Matrix

.

Metho

. .

.

. . .

. . . . . . . . . . . 2-63

.

d

. .

.

. .

.

. . . . . . 2-62

.

Measuremen

.

. .

.

. .

.

. .

.

t

.

2-44

2-45

2-46

2-47

2-48

2-49

2-52

2-57

2-59

2-60

2-67

Polarization

General

coupling

de

Mo

units

PMD

Optimizing

elength

v

a

W

Analysis

Minim

Statistical

Measuremen

PDL

Measuremen

Basic

Setting

External

Making the

Saving the Measurement Results . . . . . . . . 2-54

PDL Measurement: Power Max-Min Metho d . . . 2-55

Basic Measurement. . . . . . . . . . . . . . . 2-56

Setting up the System . . . . . . . . . . . . 2-56

External Source Preparation . . . . . . . . . . 2-57

Making the

Sa

Jones

Basic Measuremen

Setting up the System

External Source Preparation .

Measurement Pro cedure .

Making the Measurement . . . . . . . . . . . 2-64

Concepts

The

Description of

up

the

ving

Matrix

Establish the Polarization Reference Frame . . 2-63

Relativ

sign

Algorithm

modes

eects

.

the setup

tuning

de

mo

feature

um

haracterization

c

t:

t

the System

Source

.

of

Preparation

Measuremen

t.

.

Jones

e

.

s3

the

.

Contents-3

Application of the Jones Matrix . . . . . . . . 2-68

Timed Measurements . . . . . . . . . . . . . . 2-69

Polarization Maintaining Fib er Launch . . . . . . 2-69

Basic Measurement. . . . . . . . . . . . . . . 2-70

Setting up the System . . . . . . . . . . . . 2-70

External Source Preparation . . . . . . . . . . 2-71

Making the Measurement . . . . . . . . . . . 2-72

Concepts . . . . . . . . . . . . . . . . . . . 2-74

Explanation of Polarization Maintaining Fiber

Launch. . . . . . . . . . . . . . . . . . 2-74

Polarization Reference Frame . . . . . . . . . . 2-75

Basic Measurement. . . . . . . . . . . . . . . 2-76

Setting up the System . . . . . . . . . . . . 2-76

External Source Preparation . . . . . . . . . . 2-77

Choosing the Polarizers . . . . . . . . . . . . 2-77

Setting the Reference Frame . . . . . . . . . . 2-78

Checking Reference Frame Quality . . . . . . . 2-78

Setting a Circular State of Polarization . . . . . 2-78

Using the

Additional

2pt

Measuremen

Device

Measuremen

In

Measuring

Surface

Concepts

Explanation

Mathematics

ransmission

T

State of

Reference F

Measuremen

3pt

and

tegrated

P

.

of

olarization

P

olarization

P

the

of

t

.

. .

Output

of

t

Circuit

olarization

.

olarization

P

. .

.

(3pt

Ratio

Measuremen

rame .

Applications

t

Reference

Retardance

.

olarization

P

.

State

.

Reference

.

. .

Reference

.

F

an Optical

of

.

a Connector

at

.

rame)

F

.

ts

.

rames

.

of

.

rame

F

.

an

.

. .

.

Optical

.

. .

.

2-79

2-80

2-81

2-82

Basic Measurement. . . . . . . . . . . . . . . 2-83

Setting up the System . . . . . . . . . . . . 2-83

External Source Preparation . . . . . . . . . . 2-84

Making the Measurement . . . . . . . . . . . 2-85

Measurement Results . . . . . . . . . . . . . 2-85

. 2-86

.

Specialized

Measuring

Concepts

Degree of P

Measuremen

eectiv

.

olarization .

Electric Fields and P

hniques

ec

T

t

p

of

.

. . . . . . . . . . . 2-87

.

degree

e

.

olarization . . . . . . . . 2-87

.

olarization .

.

. .

.

2-86

2-87

Contents-4

3. Accuracy Enhancement and Troubleshooting

Before You Proceed . . . . . . . . . . . . . . . 3-1

Symptoms . . . . . . . . . . . . . . . . . . . 3-3

Solutions . . . . . . . . . . . . . . . . . . . 3-3

4. Printing, Saving, and Recalling Measurement Results and

Instrument Congurations

. . . . . . . . . . . . . . . . . . . . . . . 4-1

Conventions . . . . . . . . . . . . . . . . . 4-2

For Additional Information . . . . . . . . . . 4-2

Printing Measurement Results . . . . . . . . . . 4-3

Standard Printing . . . . . . . . . . . . . . 4-3

Procedure . . . . . . . . . . . . . . . . . 4-3

Customized Printing . . . . . . . . . . . . . 4-4

Results . . . . . . . . . . . . . . . . . . 4-4

Procedure . . . . . . . . . . . . . . . . . 4-5

Saving and Recalling Measurements . . . . . . . . 4-7

Saving Measurements . . . . . . . . . . . . . 4-8

Pro

Recalling

HP

ord

W

PMD:

PDL:

Timed

and

ving

Sa

Recalling

cedure

Pro

a

ving

Sa

cedure

8509 File

8509

Numeric

the

User

.

Measuremen

Recall Pro

Recall

File

cessor,

Pro

File

Matrix Eigenanalysis

Jones

elength-Scanning

v

a

W

Jones

ormat

F

Matrix

.

Measurement

Recalling

Preset

.

Conguration .

.

ts

cedure .

Results

Spreadsheet

.

and

. .

As

.

Jones

.

T

t

ormat

F

.

Instrumen

Conguration

. .

.

. .

.

. .

.

Database

and

. .

.

e

v

Sa

ormat

F

e

v

Sa

.

ormat

F

e

v

ext

.

Matrix

.

Sa

Congurations

.

. .

.

. .

.

F

v

.

. .

.

ormat

.

e

.

. 4-10

.

. .

.

Procedure . . . . . . . . . . . . . . . . . . 4-16

Recalling a User Conguration . . . . . . . . . . 4-17

Procedure . . . . . . . . . . . . . . . . . . 4-17

4-9

4-10

4-11

4-12

4-13

4-15

4-16

u

Men

y

Displa

The

5.

.

. .

.

F

The

Additional

or

PRESET

Information

Conguration

Displaying the Marker T

Displaying the P

Exchanging the P

Ellipse .

oincare Sphere .

olarization Ellipse

oincare Sphere and the P

. . . . . . . . . . . . . . . .

able .

.

. .

.

. . . . . . . .

. . 5-3

. . . . . . . . . 5-4

. . . . . . . . 5-5

olarization

. . 5-6

.

Changing the Power Display Units . . . . . . . . 5-7

Marking the CurrentPoint . . . . . . . . . . . 5-8

Changing

Holding

Clearing

Setting

the

Data

Displa

race

T

Up

y

Displa

rom the

F

to

y

date

.

y

Refresh

requency

F

.

Sphere

Automatically

.

. .

.

Contents-5

5-1

5-2

5-9

5-10

5-11

6. The System Menu

. . . . . . . . . . . . . . . . . . . . . . . 6-1

Conventions . . . . . . . . . . . . . . . . . 6-1

Optical Source . . . . . . . . . . . . . . . . . 6-2

Opening the Optical Source Setup Window . . . 6-2

Selecting an Optical Source (HP 8509A Only) . . 6-2

Selecting an Optical Source (HP 8509B Only) . . 6-3

Zero . . . . . . . . . . . . . . . . . . . . . 6-4

Initiating the Receiver Zeroing Routine . . . . . 6-4

Making Accurate Measurements . . . . . . . . 6-4

Calibration . . . . . . . . . . . . . . . . . . 6-5

Calibrating For Use With a Fixed Wavelength Source 6-7

Select the Source to be Calibrated . . . . . . 6-7

Calibrate at the Selected Wavelength . . . . . 6-8

Save and/or Apply the Calibration . . . . . . 6-10

Calibrating For Use With a Tuneable Wavelength

Source . . . . . . . . . . . . . . . . . . 6-11

Select External Source and Input Wavelength . 6-11

.

. .

.

8509B

. .

.

. .

.

y

.

Only)

.

. .

.

Calibrate at

ving

Sa

Applying

wto

Ho

Deleting

olarizers

P

ening

Op

Selecting

out

Ab

Selecting

olarizer

P

Using the

elength

v

a

W

Calibration

A

Calibration

a

ell

T

Calibration

a

.

P

the

olarizer

P

a

an

ternal

In

an

Angles

utter

Sh

the Selected

Calibrations

Calibration

a

If

.

olarizers

Window

.

olarizers

P

ternal

In

External P

the

and

8509B

(HP

v

Wa

.

is

.

. .

.

olarizer

.

olarizer .

oincare

P

only)

elength

.

. .

Applied

.

(HP

.

Displa

.

Averaging . . . . . . . . . . . . . . . . . . . 6-21

Opening the Averaging Window . . . . . . . . 6-21

Selecting DisplayAveraging . . . . . . . . . 6-21

About Display Averaging . . . . . . . . . 6-21

Selecting MeasurementAveraging . . . . . . 6-22

t

.

Windo

Range

Op

About

.

ening

Measuremen

.

Range

the

. .

.

Selecting Autorange

Selecting a Specic Gain State .

About Range

Analog Outputs

. . . .

. . . . . . . . . . . . . . . . 6-24

eraging

Av

.

w

. . . .

. . . . . . . . . . . 6-23

.

. .

.

. .

.

. . . . . . . . 6-23

. . . . . . . 6-23

.

Opening the Analog Outputs Window. . . . . . 6-24

DOP and Normalized Stokes Parameters Mode . . 6-24

.

Photo

w

Ra

Reference

ening

Op

Operation

dio

rame

F

Reference

the

erication

V

de

Info

Curren

ts

.

. .

.

F

.

Information Windo

rame

.

w

.

6-12

6-14

6-15

6-16

6-17

6-18

6-19

6-20

6-22

6-23

6-25

6-26

6-28

Contents-6

7. User Interface Reference

Main Window . . . . . . . . . . . . . . . . . 7-2

Optical Source Setup . . . . . . . . . . . . . . 7-7

Calibration . . . . . . . . . . . . . . . . . . 7-9

Operation Verication . . . . . . . . . . . . . 7-11

PMD: Jones Matrix Eigenanalysis . . . . . . . . 7-12

PMD Statistics . . . . . . . . . . . . . . . . . 7-15

PMD: Wavelength-Scanning . . . . . . . . . . . 7-18

Timed Measurements . . . . . . . . . . . . . . 7-22

PDL: Jones Matrix & Jones Matrix . . . . . . . . 7-24

PDL: Power Max - Min . . . . . . . . . . . . . 7-26

PM Fiber Launch . . . . . . . . . . . . . . . 7-28

Marker Angles . . . . . . . . . . . . . . . . . 7-29

8. Lightwave Connector Care

Introduction . . . . . . . . . . . . . . . . . . 8-1

Cleaning and Handling . . . . . . . . . . . . . 8-3

Denition of Terms . . . . . . . . . . . . . . 8-3

Connector

Adapter

Handling

Cleaning

Equipmen

Pro

Cleaning

Equipmen

cess

Pro

Cleaning

Storage

Making

Summary

ection

Insp

Non-Lensed

cess

Ligh

Lensed Connections

.

Connections

.

. .

.

. .

.

. .

.

. .

.

. .

.

. .

.

Connectors

e

v

a

w

t

Ligh

.

. .

.

t

.

. .

.

Adapters

e

v

a

w

t

.

t

.

. .

.

. .

.

. .

.

. 8-3

. .

.

Visual Inspection . . . . . . . . . . . . . . . 8-8

Optical Performance Testing . . . . . . . . . . 8-8

Introduction . . . . . . . . . . . . . . . . 8-8

Insertion Loss . . . . . . . . . . . . . . . 8-9

.

. .

.

. .

.

Return

Loss

8-3

8-4

8-5

8-6

8-7

8-8

8-9

Regulatory Information

and

y

Safet

9.

Regulations and Licensing .

Safety Information

Environmental Conditions .

Ventilation Requiremen

Cleaning Instructions

Instrument Conforms . . . . . . . . . . . . . 9-3

Laser Ap erture Lo cation . . . . . . . . . . . 9-4

. . . . . . . . . . . 9-1

. . . . . . . . . . . . . . 9-3

.

. . . . . . . . . . 9-3

ts . . . . . . . . . . . 9-3

. . . . . . . . . . . . . 9-3

Contents-7

10. Programming

11. Specications and Characteristics

. . . . . . . . . . . . . . . . . . . . . . . 11-1

Warranted Specications . . . . . . . . . . . . 11-1

Polarization Mo de Dispersion (PMD) Specications,

Jones Matrix Eigenanalysis (JME) Method (HP

8509B only) . . . . . . . . . . . . . . . 11-1

Characteristics . . . . . . . . . . . . . . . . . 11-2

Jones Matrix Eigenanalysis PMD Measurement . 11-2

Wavelength Scanning PMD Measurement . . . . 11-3

Comparison Between Jones Matrix Eigenanalysis and

Wavelength Scanning Methods . . . . . . . 11-4

Receiver Characteristics . . . . . . . . . . . . 11-5

Source Characteristics . . . . . . . . . . . . . 11-6

Polarization Dependence, Jones Matrix Method . 11-7

Polarization Dependence, Power Max-Min Method 11-7

Fiber Size and Analog Output Range . . . . . . 11-7

A. Co

P

Glossary

Index

ordinate System

t

olarized

Ligh

and Generation

of

Righ

t-Hand

Circularly

Contents-8

Figures

1-1. The HP 8509 Basic Measurement Screen . . . . 1-4

1-2. The Marker Window . . . . . . . . . . . . . 1-6

1-3. Setting a Marker . . . . . . . . . . . . . . . 1-7

1-4. Close Set Marker Window. . . . . . . . . . . 1-7

1-5. Turn Markers On/O . . . . . . . . . . . . . 1-8

1-6. Clear Markers . . . . . . . . . . . . . . . . 1-8

1-7. Center Sphere on Marker . . . . . . . . . . . 1-9

1-8. Marker Zoom and Rotate . . . . . . . . . . . 1-10

1-9. Clear Trace and Hold . . . . . . . . . . . . . 1-11

1-10.and Cal . . . . . . . . . . . . . . . . . . 1-12

Example

2-1.

Measuremen

2-2.

System

2-3.

Optical

2-4.

olarizer

P

2-5.

Polarizer

2-6.

3pt

2-7.

Circular

2-8.

JME

2-9.

2-10. JME

Segmen

2-11.

Find

2-12.

2-13. Optical

of

measuremen

Setup

t

u

Men

Source

Selection

Setup

Reference

olarization

P

Measuremen

Source

Minim

Setup

Selection

t

um

Source Setup

t .

.

Setup

.

Applied

Selection

t

of

#

. .

.

oints

P

for PMD:

.

. .

.

. .

.

. .

.

. .

Jones Matrix

.

. .

.

. .

.

. .

.

. .

2-2

2-3

2-4

2-5

2-6

2-7

2-8

2-9

2-10

PMD:JME

for a

y

displa

data

Eigenanalysis . . . . . . . . . . . . . . . 2-11

2-14. PMD: JME MeasurementStart . . . . . . . . 2-11

2-15. Measurement Results . . . . . . . . . . . . . 2-12

2-16. The Measurement Summary . . . . . . . . . . 2-13

2-17. The Measurement Annotation Area . . . . . . . 2-14

Cursor

The

2-18.

Changing

2-19.

2-20. Changing the Graph's Y-Scale

2-21. Displaying Data in T

2-22. Displaying Data in a Statistical

2-23. Displaying Data in a Statistical F

2-24. PMD Statistics File Men

Bar

Measuremen

the

t

abular F

u.

ormat

F

ormat .

.

. . . . . . . . 2-16

.

. . . . . . 2-16

. .

.

Format . . . . . 2-17

ormat . . . . . 2-18

. . . . . . . . . . 2-19

2-15

.

. .

.

2-25. Printing the PMD:JME Graph . . . . . . . . . 2-22

2-26. Saveas Text . . . . . . . . . . . . . . . . . 2-22

2-23

.

. .

.

2-24

.

. .

.

2-25

.

. .

.

2-25

.

2-27.

2-28.

2-29.

2-30.

Database

Saving

in

.

Measuremen

.

t

.

Setup

Start

.

ormat

F

.

Contents-9

2-31. Thru Calibration . . . . . . . . . . . . . . . 2-26

2-32. The Measurement . . . . . . . . . . . . . . 2-26

2-33. The Results . . . . . . . . . . . . . . . . . 2-27

2-34. Example of data displayforawavelength-scanning

PMD measurement . . . . . . . . . . . . 2-33

2-35. Wavelength-Scanning System Setup . . . . . . . 2-34

2-36. Wavelength-Scanning Measurement Selection . . 2-35

2-37. Optical Source Setup for PMD:Wavelength Scanning 2-36

2-38. PMD: WS Measurement Start . . . . . . . . . 2-36

2-39. Measurement Results . . . . . . . . . . . . . 2-37

2-40. The Measurement Summary . . . . . . . . . . 2-38

2-41. The Measurement Annotation Area . . . . . . . 2-39

2-42. The Cursor Bar . . . . . . . . . . . . . . . 2-39

2-43. Changing the MeasurementFormat . . . . . . . 2-40

2-44. Displaying Data in Tabular Format . . . . . . . 2-41

2-45. Printing your Graph . . . . . . . . . . . . . 2-42

2-46. Saveas Text . . . . . . . . . . . . . . . . . 2-43

2-47. Saving in Database Format . . . . . . . . . . 2-43

data

measuremen

Jones matrix

2-48. Example

Measuremen

2-49.

System

2-50.

Optical Source

2-51.

olarizer

P

2-52.

olarizer

P

2-53.

3pt

2-54.

Circular

2-55.

Jones

2-56.

Jones

2-57.

Measuremen

2-58.

Example

2-59.

2-60. Measuremen

2-61. System Menu . . . . . . . . . . . . . . . . 2-57

2-62. Optical Source Setup . . . . . . . . . . . . . 2-57

2-63. PDL Measurement Selection . . . . . . . . . . 2-58

2-64. PDL:Power Max-Min Measurement Window. . . 2-58

2-65. Measurement Results . . . . . . . . . . . . . 2-59

2-66. Example

Measuremen

2-67.

2-68. System Men

2-69. Optical Source Setup

2-70. Jones Matrix Measuremen

2-71. Jones Matrix Measuremen

2-72. Measurement Results . . . . . . . . . . . . . 2-66

2-73. Comparing the output Jones Vectors to 3 known

Jones

2-74.

Example

2-75.

Measuremen

2-76.

of a

.

y

displa

Setup

t

u

Men

Selection

Setup

Reference

olarization

P

Matrix

measuremen

input

Matrix

Alignment

Measuremen

t Results

PDL

a

of

Setup

t

data

of

Setup

t

u . .

Jones

Application

P

a

of

Setup

t

.

. .

.

Setup

.

Applied

measuremen

.

displa

.

t

.

. . . . . . . . . . . . . . 2-62

ectors

V

olarization

displa

data

.

PDL

.

. .

.

. .

.

. .

.

Selection

t

Windo

t

.

. .

.

for

y

. .

.

. . . . . . . . . . . . . 2-62

t Selection

t Windo

.

Maintaining

.

y

.

w

.

displa

data

t

.

matrix

Jones

a

.

w . . . . . . 2-65

.

t

. .

.

. .

.

. .

.

y

.

. .

. . . . . 2-64

.

. .

.

er

Fib

.

2-47

2-48

2-49

2-50

2-51

2-52

2-53

2-55

2-56

2-60

2-61

2-68

2-69

2-70

Contents-10

2-77. System Menu . . . . . . . . . . . . . . . . 2-71

2-78. Optical Source Setup . . . . . . . . . . . . . 2-71

2-79. PM Fib er Launch Measurement Selection . . . . 2-72

2-80. PM Fib er Launch AlignmentWindow. . . . . . 2-73

2-81. How PMF cable launch extension ratio is calculated 2-74

2-82. Example of the results that can be achieved with and

without a polarization reference frame . . . . 2-75

2-83. Measurement Setup . . . . . . . . . . . . . . 2-76

2-84. System Menu . . . . . . . . . . . . . . . . 2-77

2-85. Optical Source Setup . . . . . . . . . . . . . 2-77

2-86. Example of a SOP measurement data display . . 2-82

2-87. Measurement Setup . . . . . . . . . . . . . . 2-83

2-88. System Menu . . . . . . . . . . . . . . . . 2-84

2-89. Optical Source Setup . . . . . . . . . . . . . 2-84

2-90. SOP and DOP Measurement Example . . . . . 2-85

2-91. Polarization changes with Ex(t) and Ey(t). . . . 2-87

2-92. Elliptical displays of polarization . . . . . . . . 2-88

2-93. Mathematical description of an elliptical displayof

2-88

.

. .

polarization

olarization

P

2-94.

Measuremen

3-1.

Men

File

The

4-1.

The Prin

4-2.

Customized

4-3.

The

4-4.

The

4-5.

The

4-6.

Viewing

4-7.

The

4-8.

The

4-9.

The

4-10.

4-11. The

4-12. The Load Menu . . . . . . . . . . . . . . . 4-17

4-13. The Load Window . . . . . . . . . . . . . . 4-17

5-1. The PRESET Conguration . . . . . . . . . . 5-2

5-2. The Show Markers Menu . . . . . . . . . . . 5-3

5-3. Marker Window Hidden . . . . . . . . . . . . 5-3

5-4. The

oincare

P

5-5.

The

5-6.

5-7. P

5-8. The Sho

5-9. Sphere and Ellipse Exc

5-10. The P

5-11. Power Display in Watts Mode . . . . . . . . . 5-7

5-12. The Mark CurrentPointMenu. . . . . . . . . 5-8

5-13.

5-14.

5-15.

5-16. The

5-17.

olarization Ellipse T

Mark

The

t

Men

e

v

Sa

As Windo

e

v

Sa

Load

a

Load

Preset Conrmation

Men

e

v

Sa

File

w

Sho

Sphere

w

Sho

w Sphere

ower Displa

Curren

Displa

Hold

. .

states

roublesho

T

t

.

u

Men

ting

Prin

u

Men

Stored

PRESET

u

As:

e

v

Sphere

T

Ellipse

oin

P

t

date

Up

y

date

Up

y

u

Men

unction

F

oincare

P

a

on

Matrix

oting

.

. .

.

the

.

O .

ated

.

. .

.

P

.

File

.

Example

.

w

.

on

race

T

Conguration

Window

.

Congure

.

u

Men

urned

Men

<->

yMen

O .

.

u

urned

Ellipse Men

hanged .

u . . . . . . . . .

Activ

t

u

Men

Box

.

. .

.

Sphere

.

u

.

w

. .

.

. .

.

. .

.

. .

.

. . 5-7

.

. 4-15

.

. 5-10

Sphere

.

oincare

Men

.

Windo

.

. . . . . . . . 5-5

u . . . . . . 5-6

. . . . . . . . 5-6

.

2-89

3-2

4-1

4-3

4-4

4-8

4-9

4-10

4-11

4-15

4-16

5-4

5-5

5-8

5-9

5-10

Contents-11

5-18. The Clear Trace Menu . . . . . . . . . . . . 5-11

5-19. The Auto Refresh Menu. . . . . . . . . . . . 5-11

6-1. The HP 8509A Optical Source Window . . . . . 6-2

6-2. The HP 8509B Optical Source Window . . . . . 6-3

6-3. The Calibration Window . . . . . . . . . . . 6-5

6-4. The Optical Source Window. . . . . . . . . . 6-7

6-5. The Calibration Window . . . . . . . . . . . 6-9

6-6. The Calibration List . . . . . . . . . . . . . 6-10

6-7. The Optical Source Window. . . . . . . . . . 6-11

6-8. The Calibration Window . . . . . . . . . . . 6-13

6-9. The Calibration List . . . . . . . . . . . . . 6-14

6-10. Calibration Applied . . . . . . . . . . . . . . 6-16

6-11. Deleting a Calibration . . . . . . . . . . . . 6-17

6-12. Conrm or Abort the Deletion Process . . . . . 6-17

6-13. The Polarizers Window . . . . . . . . . . . . 6-18

6-14. The Shutter Menu . . . . . . . . . . . . . . 6-20

6-15. The Averaging Window. . . . . . . . . . . . 6-21

6-16. The Range Window. . . . . . . . . . . . . . 6-23

6-17. The

No

6-18.

Tw

6-19.

Three-P

6-20.

The Op

6-21.

Laser

9-1.

Comparison

11-1.

Analog Outputs

rame

Reference

t

Reference

t

oin

eration

.

erture

of

Optical

F

V

.

JME

.

Lo

Reference

oin

o-P

8509A

Ap

Long

for

Window

Dened

rame

F

rame Information

F

erication

.

cation

and

er

Fib

.

Windo

w

Information

the

for

Windo

.

w

.

WS Measuremen

.

est

T

.

Windo

Window

HP

.

. .

Metho

t

.

w

.

ds

.

6-24

6-26

6-27

6-28

9-4

11-4

Contents-12

Tables

4-1. Summary of HP 8509 Measurement Results

Save/Recall Features . . . . . . . . . . . . 4-6

6-1. Analog Outputs for DOP and Normalized Stokes

Parameters Mo de . . . . . . . . . . . . . 6-24

6-2. Analog Outputs for Raw Dio de Currents Mode . . 6-25

7-1. Main Window . . . . . . . . . . . . . . . . 7-2

7-2. Optical Source Setup . . . . . . . . . . . . . 7-7

7-3. Calibration . . . . . . . . . . . . . . . . . 7-9

7-4. Operation Verication . . . . . . . . . . . . 7-11

7-5. PMD: Jones Matrix Eigenanalysis . . . . . . . 7-12

PMD Statistics

7-6.

7-7. PMD:

Timed

7-8.

PDL:

7-9.

PDL:

7-10.

PDL:

7-11.

Mark

7-12.

Maxim

11-1.

8509B)

11-2. PMD

Metho

Rep

11-3.

Pigtail

Repeatabilit

11-4.

v

a

W

Measuremen

Jones

w

o

P

ow

P

Angles

er

um

Measuremen

d

eatabilit

. .

elength-Scanning

.

ts

Jones

.

of

&

Min .

-

Min

-

.

Uncertain

t

8509B

JME

.

PMD

.

DGD

.

Only)

. .

Matrix

Max

er

Max

er

Measurable

.

(HP

y

ositions .

p

y

.

Matrix

.

. .

.

Using

.

. .

Using

y

t

.

Measuremen

. .

Measuremen

.

JME

.

. .

.

the

.

. .

.

Dela

.

JME

.

with

t

.

with

t

.

. .

.

y

.

(HP

.

Fixed

.

. 7-22

.

. .

Randomized Pigtail Positions . . . . . . . . 11-3

11-5. Minimum Measurable PMD Using the Wavelength

Scanning Method . . . . . . . . . . . . . 11-3

11-6. Receiver Characteristics . . . . . . . . . . . . 11-5

11-7. Source Characteristics . . . . . . . . . . . . . 11-6

.

External Source

11-8.

Measuremen

11-9.

Only) Jones

11-10. Measuremen

Only) P

Input

olarization

P

of

t

Matrix

olarization Dependence (HP

tofP

ower Max - Min Metho d

11-11. Other Characteristics .

Characteristics

ort

P

Dep

Metho

d

. . . . .

endence (HP

.

. . . . . . 11-7

. . . . . . . 11-7

.

8509B

.

8509B

7-15

7-18

7-24

7-26

7-28

7-29

11-1

11-2

11-6

11-7

Contents-13

Getting Started

This chapter contains the following sections.

Description of the Instrument

Installation

About This Manual Set

The Main Menu

The Data Displays (Power, DOP, Ellipse and Poincare Sphere)

The Marker Functions

Rotate

and

om

Zo

1

Description

Installation

of

Instrument

the

4

race

T

r

Clea

45

and

HP

The

calibrated

componen

Cal

8509A/B

p

ts.

Hold

and

5

Ligh

olarization

P

e

v

a

w

t

measuremen

ts

of

optical

Analyzer

signals and

oers

high-sp

The lightwave polarization analyzer is precongured at the

factory. All that is required to install the system is to unpackthe

the

to

Refer

on.

pieces,

correctly

\Installation"

Start Guide

also pro

system to

vides instructions for unpac

the factory for service.

connect

hapter

c

of

them,

the

and turn

8509A/B

HP

for complete instructions. The \Installation" c

them

Quick

Instal

lation

and

hapter

king the system and returning the

eed,

Getting

Started

1-1

About This Manual Set

The HP 8509A/B manual set is made up of three documents.

HP 8509A/B LightwavePolarization

Installation Quick Reference Card

Installation and Quick Start Guide

User's/Reference Guide (this manual)

This guide uses the following conventions:

4

Button

5

This represents a button that can be selected on the

computer screen to perform an action.

N

Menu

Item

This

NN

N

NN

N

the

contains an installation procedure.

contains an installation procedure, and an operation

verication procedure to ensure that your analyzer is

operating prop erly.

this is the main manual for the lightwave polarization

analyzer. This manual is describ ed in detail later in this

chapter.

indicates

computer

men

a

screen.

u

item

that

can

e

b

selected

on

1-2

Getting

Started

HP 8509A/B User's/Reference Guide Table of Contents

(this manual)

This manual contains the following chapters.

1.

Getting Started

describes the HP 8509A/B manual set, and provides a

description of the Main Menu screen of the software.

2.

Making Measurements

provides step-by-step instructions for making the following

measurements.

Polarization Mode Disp ersion: Jones Matrix Eigenanalysis

Method (PMD JME)

Polarization Mode Disp ersion: Wavelength-Scanning Metho d

(PMD WS)

Polarization Dependent Loss: Jones Matrix (PDL JM)

Polarization Dependent Loss: Power Max-Min Method

Jones Matrix

Polarization Maintaining Fiber Alignment

Polarization Reference Frame

olarization

P

of

State

olarization

P

Degree

of

3.

Accuracy

roublesho

T

ting,

Prin

4.

Measuremen

Instrumen

Displa

The

5.

System

The

6.

terface

User

Ligh

Safet

In

a

w

t

and

y

7.

8.

9.

Information

10.

Programming

11.

Specications and

Characteristics

Glossary

Index

Appendix

Enhancement

oting

ving,

Sa

Results

t

Congurations

t

Men

y

u

Men

Reference

Connector

e

v

Regulatory

and

u

and

Recalling

and

Care

measuremen

File

Displa

System

reac

to

of

u.

men

y

men

and

it,

h

connectors.

and

u.

a

solving

vides

eac

ws

procedures

information

a

provides

and

pro

sho

description

information on

vides

pro

licensing,

vides

pro

measurement

description of

description

and

trol

con

h

what

of

safet

for impro

problems.

out

ab

the

of

displa

es.

do

it

caring for

regulatory

,

y

ving the

items

the

items

the

,

y

accuracy

the

in

the

in

the

in

path

the analyzer's

cleaning,

,

environmental information.

provides guidance for programming problems.

provides performance sp ecications and characteristics of the

lightwave polarization analyzer.

denitions.

their

and

terms

of

list

alphab

etized

list of

terms

with

page

n

um

er

b

pro

vides

an alphab

an

references. This is a subject index.

provides specialized bac

kground information.

ts

Getting

Started

1-3

The Main Menu

This chapter describes the functions that are available from the basic

measurement screen. Subsequentchapters describe functions that are

accessed through the main menu shown in this screen.

File

Edit

Measurement

Display

System

Help

The

are

t

man

Screen

Results

ual.

Figure

main men

Most

\Prin

Instrumen

1-1.

selections

u

the

of

ting,

8509 Basic

HP

The

are:

items

u

men

and

ving,

Sa

Congurations"

t

under

Recalling

hapter

c

Measurement

selection

this

Measuremen

this

of

This selection allows you to copy the display or a measurement

window to the Clipb oard.

The measurement selections are discussed in the \Measurement

Applications" chapter of this manual.

The items in the Display menu are discussed in \The Display

ual.

man

this

hapter

c

u"

Men

system

The

chapter of this man

The online help function is not a

of

functions

ual.

are

describ

\The

in the

ed

vailable at this time.

explained

and

System

in

Men

the

u"

1-4

Getting

Started

The Data Displays (Power, DOP, Ellipse and Poincare Sphere)

Refer to Figure 1-1 for the location of the displays on the basic

measurement screen.

Power Display

DOP Display

Poincare Sphere

The power of the optical signal under test is displayed as b oth a

horizontal bar, and a digital readout. When the receiver zeroing

routine is b eing performed, a green \zero" message appears in the

power display. Red \Overrange" and \Underrange" messages appear

here also.

The Degree of Polarization (DOP) is displayed as both a horizontal

bar and a digital readout. For the most reliable and accurate

measurements, use polarized light that approaches 100% DOP.

The HP 8509 Poincare sphere is a three-dimensional graphing system

showing all possible states of polarization. A dot or trace on the

sphere represen

allo

inside

ws

relativ

measured

feature

olarization

p

ADDITIONAL

oincare

P

the

Since

know

helpful

solid

the

on

to

lines

sphere.

bac

the

on

Data

k

of

ts the

the

INF

the

instrumen

the

oincare

P

to a

e

ORMA

sphere

that

fron

on

sphere is

ortion

p

polarize

d

t's

sphere

receiv

to

user-dened reference

TION

three-dimensional

a

is

sphere,

the

of

(equator

in

the

t

the

of

graticules

the

t

fron

shown

of

er.

displa

and

sphere

blue.

ligh

the

The

signal's state

a

y

and

en

brok

sho

is

e

v

a

w

t

reference

frame.

represen

longitude

on

lines

in red,

wn

signals

as

frame

of

tation, it

lines)

bac

the

and

is

are

of

k

data

olarization Ellipse

P

polarization

The

ellipse pro

vides

o-dimensional

w

t

a

visual

representation of the state of p olarization of an optical signal and

corresponds with points on the Poincare sphere.

Getting

Started

1-5

The Marker Functions

The mark

displa

ys

a

alw

s2

top

p

and

line

optical

(s1,

the

er windo

ys

(S0),

er

w

o

s3).

4

(

5

s

the

Stok

of

)

Figure

the

w, in

es

Stok

dBm,

in

parameters for

es

mark

the

Mark

The

1-2.

left

er

w

lo

parameters,

the

and

table.

er

Windo

er

corner

of

comprised

normalized

curren

the

w

the

of

Stokes

data

t

8509

HP

the

parameters

p

v

a

oin

displa

erage

are

t

on

,

y

Setting a Mark

A,

adjacen

ed

y

information

hapter

c

ts"

mark

wing

marker

to

t

on

of

functions

er

resp

the

es

Stok

this man

mark

e

ectiv

parameters,

ual.)

discussed in

are

button

er

to

refer

this section.

the

displa

e

marker

or

(F

When

b

C).

Measuremen

follo

The

Setting a

parameters

e

ectiv

resp

the

set,

is

C

or

B,

Turning the markers on and o

Clearing the markers

Centering the sphere on a marker or currentpoint

frames

oincare sphere:

or

er

p

t

o- and

Tw

There are t

set a mark

a marker at a user-specied poin

set

three-p

wow

er at the curren

where the curren

oin

to set mark

ays

t data poin

olarization

ers on the P

t data poin

t is)

reference

t,

t on the sphere (regardless of

In b oth of these cases, when a marker is set, the Stokes parameters

for the particular marker (A, B, or C) always appears in the table

app

to

er

mark

the

for

er,

ev

w

Ho

w.

windo

the Mark

in

oincare

P

ers

sphere,

the

Mark

ers

m

ust

e

b

turned

\on."

will

B,

(A,

\Making

on

ear

also

or

the

1-6

Getting

Started

Setting a Marker at the Current Data Point

1. Select

4A5,4B5or4C5

(on the left side of the Marker window) to set

amarker on the Poincare sphere at the current data point. (See

Figure 1-3.)

Once a marker has b een set, the Stokes parameters for the marker

point will be displayed in the marker table.

ADDITIONAL INFORMATION

Once a marker has been set, it is xed on the sphere and cannot be

adjusted to move along a trace.

er

Mark

Figure

1-3.

Setting

a

oint

on

ears

or

oin

p

a

the

P

t

mark

mouse.

elow

b

to

C

on

set

the

er.

the P

a

fron

oincare

mark

t

er

face

at

the

of

sphere

the

(see

place

Setting

v

Mo

1.

sphere

Double-clic

2.

The

Figure 1-4

Use

3.

a

e

Set

the

Mark

the

where

Mark

mouse

at

er

mouse p

ou

y

the

k

er

).

to

User-Specified

a

to

ter

oin

place

to

t

an

w

button

left

app

w

windo

A,

select

the

B,

the sphere where you double-clicked the mouse.

4. Notice that the Stokes parameters for that point appear in the

marker table in the marker window.

5.

ou

y

If

mark

v

ha

window,

er

decided

e

not

select

to set

None.

a

the

close

to

wish

and

er

mark

Figure 1-4. Close Set Marker Window

on

Set

Getting

Started

1-7

Turning the Markers On and Off

When the markers are turned on, there is an \X" in the Markers On

box (see Figure 1-5).

When

parameters

the

When

the

in

sphere.

the

oincare

P

the

mark

app

sphere.

mark

er

Figure 1-5. Turn Markers On/Off

y

and

mark

the

on

er

o,

mark

table,

the

er will

Stok

ers

ear

ers

table,

are

in

are

turned

the

turned

but

ou

and

set

not

mark

a

mark

the

parameters

es

ear

app

er,

on

er

the

app

still

the

Stok

ears

app

oincare

P

es

on

ear

Clearing

the

Mark

ers

Select

Stok

the

and C.

4

Clea

es

Ma

r

data

ers

rk

in

Figure 1-6. Clear Markers

mark

the

e

v

remo

5

to

table

the mark

er

asso

ers

ciated

from

the

with

sphere

mark

ers

and

A,

clear

B,

1-8

Getting

Started

Centering the Sphere on a Marker or Current Point

Figure 1-7. Center Sphere on Marker

The buttons along the right side of the marker b ox correspond to the

current data point and the three markers. These buttons can be used

to rotate the sphere so that the selected p ointormarker is front and

ter.

cen

Tw

or Three-P

o-

oint P

olarization

or

F

reference

man

Reference

information

frame,

ual.

setting a

on

refer

to

the

or

o-

tw

\Making

three-p

oin

Measuremen

olarization

p

t

ts"

hapter

c

of

this

Getting

Started

1-9

Zoom and Rotate

Zoom

Figure 1-8. Marker Zoom and Rotate

To Zoom In

To zoom in on data on the Poincare sphere, select either

4

Out

6

decrease

to

ys:

a

w

o

immediately

to

use

to

ts

5

Use

advance

to

Zoom

o

T

zo

o

T

om

zo

factor

The

ou

Y

Select

the

4

5

In

7

om

factor

more

Zoom

can

zo

advance

to

the

Out

out,

in

rapidly

actor

F

the

use

this

factor bac

om

zo

select

incremen

.

Function

om

zo

function

the zo

factor

either

ts of

factor

in

kto

om factor

more

4

5

Out

6

one.

function

omed

zo

a

1 without

in incremen

rapidly

4

or

5

66

Use

in

condition

having

4

.

66

.

Use

5

w

t

one.

of

decrease

to

the

4

In

7

Use

zo

\Out"

5or4775

om

bring

buttons.

Select this function when the factor is 1 to set the zoom factor to

the most recently visited zoom factor.

4

77

the

.

5

1-10

Getting

Started

Rotate

To Rotate the Sphere

To rotate the sphere, select any of the four arrows in the Rotate

area (see Figure 1-8). The sphere will rotate in the direction of the

selected arrow.

The

4

5

Button

Home

4

Clea

CAUTION

To bring the sphere back to the default orientation, select

Any time you rotate the sphere, the trace is cleared. The only

4

Home

5

.

exception to this is when you are viewing a recalled data trace or

a timed measurement. (See the \Printing, Saving and Recalling

Measurement Results and Instrument Congurations" chapter in this

manual.) In these cases, the recalled trace will not be cleared as the

sphere is rotated.

Hold

and

5

race

T

r

Figure

1-9.

Clear

Trace and

Hold

4

ClearTrace

Hold

Select

5

4

ClearTrace

5

to clear the Poincare sphere of previously displayed

data points. The HP 8509 will immediately resume data display

unless the Hold function has been activated.

When

sphere

Hold

displa

,

y

the p

activated,

is

ellipse, or the Stok

Hold function is activ

is toggled on and o b

the instrumen

ton

computational activit

the

the p

,

y

displa

DOP

the

,

y

displa

er

w

o

es parameters (in the Marker windo

ated, there is an \X" in the Hold bo

y selecting Hold (see Figure 1-9). Putting

HOLD

dramatically sp eeds up graphics and

y in the computer. Put the HP 8509 in

date

up

not

es

do

8509

HP

when running other software programs.

Getting

oincare

P

the

olarization

w). When the

x. Hold

HOLD

Started

1-11

45

and Cal

Figure 1-10.and Cal

Source

W

a

elength

v

45

Cal

Select

45

to show the Optical Source window. Refer to \The System

Menu" chapter of this do cument for more information on the Optical

Source window.

user-p

a

calibration

k)

hapter

ecic

4

function.

5



erformed

lettering.

ears

app

do

this

of

calibration.

b

has

a

If

gra

in

cumen

een

y

for

t

source

The

function indicates

Cal

The

calibration

applied,

the

calibration

lettering.

instructions

elength is

v

a

w

b

has

ord

w

not

has

Refer to

p

on

applied.

een

\Cal"

een

b

\The

erforming

display

whether or

If

ears

app

applied,

System

a

w

a

ed next

v

a

w

a

b

in

the

Men

elength

v

to the

not

elength

(blac

old

ord \Cal"

w

c

u"

sp

1-12

Getting

Started

Making Measurements

This chapter contains information on the following measurements.

1. Jones Matrix Eigenanalysis Method, PMD Measurement

2. Wavelength-Scanning Method, PMD Measurement

3. Jones Matrix Metho d, PDL Measurement

4. Power Max-Min Metho d, PDL Measurement

5. Jones Matrix Measurement

6. Polarization Maintaining Fib er Launch

2

Conv

entions

olarization

P

7.

State

8.

measuremen

The

Description

erforming

P

Setting

olarization

P

of

up

Reference

in

ts

the

of

basic

a

System

the

F

Measurements

hapter

c

this

measuremen

t

tend

and

an

Measuremen

rame

Source Preparation

Making

the Measuremen

t

Manipulating the Measurement Results

Specialized Measurements

Measurement Specic Concept Information

follo

to

example

t

outline;

this

w

y

displa

data

4

5

Button

NNNNNNNNNNNNNNNNNNNNNNNNN

N

Menu Item

This represen

ts a button that

computer screen to perform an action.

NNN

This indicates a men

u item that can be selected on

the computer screen.

can b e selected on the

Making

Measurements

2-1

PMD Measurement: Jones Matrix Eigenanalysis Method

Polarization mo de dispersion (PMD) is a fundamental physical

property of optical ber and components in whichalightwave is split

into twowaves of slightly dierent speed on the basis of polarization

state. At a given wavelength, these two polarization modes

experience a dierence in propagation time known as \dierential

group delay" (DGD). The DGD of long optical bers varies with

wavelength. The \PMD" of a test device also refers to the average

value of the dierential group delay. PMD is fundamentally

expressed in units of time, typically picoseconds (1 ps = 10

the case of long bers, it may be normalized to the square ro ot of

ber length with the units of picoseconds per ro ot kilometer.

This section explains how to measure the PMD of a test device using

the Jones matrix eigenanalysis (JME) method, available in the HP

8509B. A typical measurement result, showing the dierential group

delay as a function of wavelength, is shown in the following gure.

0

12

s). In

2-2

Making

Measurements

data

Figure

2-1.

Example

of

Typical applications of the JME

PMD:JME

for a

y

displa

method include measuremen

measurement

tof

EDFA's, couplers, isolators, bers, and optical connectors. Cables

number of ampliers and b er spans

and systems consisting of an

can also b e tested. Consider the follo

method when deciding whic

y

wing aspects of the JME

PMD measurement method to use:

h

Dierential group delay (DGD) is measured as a function of

elength.

v

a

w

Measuremen

v

a

w

narro

lo

of

t

elength

PMD

w

range.

comp

onen

ts

can

accomplished

e

b

with a

PMD Measurement: Jones Matrix Eigenanalysis Method

The measurement is independent of pigtail position and

polarization launch condition.

Optical ber DGD data can be shown in a histogram and

compared with the expected distribution to assess the statistical

condence of the measurement.

Basic Measurement

System

the

Setting

up

The following measurement procedure illustrates the simplest

and most straightforward path in using the HP 8509B Lightwave

Polarization Analyzer to make a PMD:JME measurement. Other

specialized measurement applications and techniques are included

later on in this section.

Connect

y

illustration.

er

b

8509B

t

en

vemen

source

an

t

.

external

CCURA

A

The

HP

accuracy

measuremen

our

Install

CY

cable

the

olarization.

p

ENHANCEMENT

leading

EXTERNAL

t after

vemen

mo

y

source

this

of

t

thru

from

SOUR

cable

system

cable

external

the

CE

source

ma

outlined

as

the

for

NOTE

INPUT

olarization

p

jeopardize

y

in

one-time

source

ust

m

has

PMD

the follo

adjustmen

the

to

e

b

wing

t

wn to

do

ed

tap

adjusted.

een

b

measuremen

of

t

Figure

Measurement

2-2.

Setup

Making

Measurements

2-3

PMD Measurement: Jones Matrix Eigenanalysis Method

External Source Preparation

Before performing the PMD:JME measurement, external source

polarization must be adjusted via the two knobs on the front panel of

the HP 8509B. The following pro cedure will guide you through the

process.

ADDITIONAL INFORMATION

The 8509B uses an internal three-state, switchable polarizer to

condition the light before it is applied to the device under test.

Adjustment of external source polarization via the front panel knobs

is done to provide a roughly circular state of polarization within the

polarizer assembly, so that all three polarizers will pass high levels of

adjustmen

This

er.

w

o

optical

the

source

that the

eginning

b

p

t

fron

and

adjustment

panel

the

of

a

knobs

HP

long

8509B

b

series

the

or

erformed

p

e

of

hav

t

er

b

emo

tests.

ypically

t

connecting

ved.

once

need

How

w

a

ev

eek

not

the

er,

b

tunable

it

once

or

eated

rep

e

optical

recommended

is

the

at

unless

2-4

Making

Measurements

T

then

select

N

NN

N

Optical

the optical

up

set

o

by selecting the

window.

N

NN

N



Figure 2-3. System Menu

N

source,

NN

N

Source

button

select

N

NN

N

.Y

ou

System

ma

in the upper righ

N

NN

N

NN

from

set

also

y

up

the

main

the

optical

t hand corner of the main

menu,

source

and

PMD Measurement: Jones Matrix Eigenanalysis Method

Figure 2-4. Optical Source Setup

Select the external, tunable laser source and set the wavelength to

the approximate center of the widest range you expect to use in

your JME PMD measurements. Use the default power level or set as

desired. If the screen on your computer looks similar to the previous

illustration, select

4

Done

5

.

Select

NNNNNNNNNNNNNNNNNNNN

System

olarizer

Figure

from the main menu, and then select

2-5. P

Selection

Making

Measurements

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Polarizers

2-5

PMD Measurement: Jones Matrix Eigenanalysis Method

Figure 2-6. Polarizer Setup

Set the p olarizers to

4

Internal

5

and select

4

No Polarizer

5

. If the screen on

your computer looks like the previous illustration, select

Figure 2-7.

Select

N

3pt Ref

from the Markers Area on the Main Screen, wait 5

N

NN

seconds, and then select

Reference

3pt

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Apply 3pt

.

Applied

4

Done

5

.

2-6

Making

Measurements

ADDITIONAL INFORMATION

mea-

ws

ph

allo

ysical

frame

Creating

suremen

t

and

of p

applying

olarization

a

3pt

state

reference

within

frame

a

In this case, the reference frame is lo cated inside the in

polarizer assem

bly.

reference.

of

ternal

PMD Measurement: Jones Matrix Eigenanalysis Method

olarization

oin

p

NN

N

Mark

P

on the

t

alue

see

to

N

NN

Current

knobs

of

b

NN

N

on

Poincare

s3

the

marking

y

N

NN

Point

fron

the

mark

the

N

NN

N

).

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Apply 3pt

panel

t

sphere

is

er

curren

Also

greater

Circular

Source

the

oin

p

e

N

and

2-8.

olarization

P

e

activ

absolute v

easier

is

t

N

then

the

HP

hes

Adjust

of

approac

than 0.90.

(select

t

oin

p

External

8509B

The activ

un

ole,

p

a

N

NN

N

Display

Figure

til

and the

N

notice that the polarization ellipse will become more circular as s3

approaches 0.90. Un-apply the 3pt reference (reselect

before going on to do the JME PMD measurements. Do not move

the cable or the external source polarization knobs.

F

OR

MORE INF

ORMA

More information on State of P

gree of P

olarization (DOP) ma

TION

olarization (SOP) and De-

ybefound

in the glossary and in this

chapter.

t

)

Making

Measurements

2-7

PMD Measurement: Jones Matrix Eigenanalysis Method

Making the Measurement

At this pointyour measurement system is ready to makeyour

rst measurement. For our purposes we are going to measure a 10

kilometer sp ool of optical ber. Remove the b er cable connecting

the optical output to the optical input on the HP 8509B. Connect

your test device between the optical output and the optical input.

ACCURACY ENHANCEMENT NOTE

The ber path leading from the optical output of the

HP 8509to the DUT and from the DUT to the optical input of

the HP 8509 must not move during the measurement process.

Unsupported ber, particularly unjacketed ber, should be tap ed

down or placed against stationary ob jects. Movement of the ber

may jeopardize PMD measurement accuracy.

CAUTION

Observe proper connection techniques. Refer to the \Lightwave

Connector

Care" c

Figure

hapter in

2-9.

this

Measurement

JME

Selection

ual.

man

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Select

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Measurement

from the main menu, and then select

PMD:Jones Matrix Eigenanalysis... F2

2-8

Making

Measurements

PMD Measurement: Jones Matrix Eigenanalysis Method

Figure 2-10. JME Source Setup

Verify that the source and start and stop wavelengths are correct for

your measurement, and that the optical power is turned on. If the

screen on your computer looks like the previous illustration, select

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Find Minimum # of Points

.

ADDITIONAL

matrix

Jones

The

(DGD)

y

dela

alues

v

DGD

the

than

less

wish the

ou

y

If

the

to

in

ter

en

v

a

w,

windo

displa

lasers

ORMA

INF

from

obtained

b

um

n

source

w

o

p

no

alue

v

a

of

y

TION

eigenanalysis

optical

of

pairs

completed

a

in

measuremen

of

er

remain

to

displa

el

lev

er

greater

ailable

than

laser p

method

measuremen

wa

t

eled

lev

the

of

y

minim

the

er.

ow

computes dieren

the

so

ts,

actually

is

t

ts.

oin

elength

v

during

optical

um

p

measuremen

the

source

er sho

w

o

p

setup

tial

um

n

wn in

group

er

b

one

t,

the

of

Making

Measurements

2-9

PMD Measurement: Jones Matrix Eigenanalysis Method

Figure 2-11. Segment Selection

The window is called Find Minimum # of Points. Sample

measurements will be performed to identify the maximum DGD of

the DUT. The number of points will be set to accommodate this

alue.

v

range.

.

4OK5

Sample

or

F

measuremen

this

ts

spaced

enly

ev

are

default

the

use

t,

across

setting b

the

y selecting

elength

v

a

w

ORMA

y

INF

e

b

(Cho

on

found

osing

OR

F

More

oin

p

this

MORE

information

ma

ts

hapter

c

Statistics/Enlarging

Figure 2-12. Find Minimum # of

TION

selecting

the

in

Delta

Sample

the

appropriate

the

\Concepts"

elength

v

Wa

Size).

section

and

um

n

later

Fib

Points

er

b

on in

PMD

of

When the automatic routine is nished, you will be advised what

minimum number of measurementpoints is required for your

automatically

is

ts

oin

p

of

er

b

um

n

um

minim

elength

v

a

w

tered

en

closed.

range.

the

in

Select

The

optical

4

to

5

OK

source

tin

con

setup

with the

ue

windo

measuremen

w

when

this

t.

message b

is

x

o

2-10

Making

Measurements

PMD Measurement: Jones Matrix Eigenanalysis Method

ACCURACY ENHANCEMENT NOTE

When measuring components, polarization maintaining

ber, or short lengths of single mode b er, use the indicated

minimum number of points. When measuring long ber, or any

device that is expected to exhibit wavelength dependentPMD,

increase the number of points to measure the wavelength dependent

behavior of the device.

PMD:

2-13.

Jones

Matrix Eigenanalysis

Select

Optical

4

5

Done

Source

this

on

Setup

windo

Figure

for

w.

Figure 2-14. PMD: JME Measurement Start

Select

4

Sta

Measurement

rt

5

The JME graph is deriv

performed across the selected w

progresses, the

Measurement Summary

the

from

ed from a series of optical measuremen

velength range. As the measuremen

a

8509B

HP

graph lists the PMD results obtained, up

Graphs

display bar directly belo

to the curren

screen.

The axes of the PMD graph are annotated as dieren

in picoseconds and wavelength in nanometers.

ts

wthe

avelength.

tw

tial group dela

t

y

Making

Measurements

2-11

PMD Measurement: Jones Matrix Eigenanalysis Method

Y

lo

our

ok

similar

measuremen

the

to

Figure

complete.

is

t

2-15.

illustration.

The

screen

Results

our

y

on

computer

should

2-12

Making

Measurements

PMD Measurement: Jones Matrix Eigenanalysis Method

Manipulating the Measurement Results

When your measurement is complete, you may;

The Measurement

Summary

Review the results in the

Review the measurement setup conditions in the

Annotation

area.

Measurement Summary

bar.

Measurement

Examine the dierential group delay at a particular wavelength, by

using the cursor bar.

Display, edit, and print the data in tabular form.

Print the graph with or without measurement annotation and data

listing.

Saveyour measurement and annotation information to a database

for future use, or to reload the measurementbackinto the

HP 8509A/B.

Sa

measuremen

our

y

e

v

t

with

use

for

le

text

a

as

data

spreadsheets.

Graphs

the

windo

ving

w,

using

windo

ws

erform

P

windo

Display

or

tile

other

w.

all

cascade

of

PMD

our

y

mo

des.

measurements

measuremen

without lea

one

in

ts

Bar

Figure

The

Measurement Summary Bar

up to the curren

All of the

displays ha

2-16.

avelength.

tw

ve the same units, whic

displays the PMD

Measurement

The

but default to picoseconds. The bar displa

Summary

results obtained

h are user selectable

ys the a

verage, curren

t,

maximum, minimum, and standard deviation () of the dierential

group delay, up to the currentwavelength.

Making

Measurements

2-13

PMD Measurement: Jones Matrix Eigenanalysis Method

The Measurement Annotation Area

Figure 2-17. The Measurement Annotation Area

When the measurement ends, the control panel at the b ottom of the

Graphs window is replaced by

lists the date and time of the start of the measurement, the ber

length in kilometers, the tunable laser power and attenuator settings,

a

w

stop

and

start

the

b

um

n

the

lists

also

It

optical measuremen

h

whic

at

b

can

annotation

main

the

area

windo

w

men

elengths

v

of p

er

toggled

e

u, and

Measurement Annotation

elength

v

a

w

the

and

um

N

tak

N

the n

measuremen

The

en.

selecting

y

b

o

N

NN

.

oints,

ts w

then

that is,

ere

and

on

N

Annotation

in

er

b

. This area

or delta.

terval

v

a

w

of

NN

N

Display

elengths

t

N

from

ADDITIONAL

matrix

Jones

The

n

um

dela

er

b

one

tial group

the

so

actually

is

ORMA

INF

eigenanalysis

(DGD)

y

DGD

of

than

less

from

alues

v

the

TION

adjacen

obtained

umb

n

metho

er of

d computes

of

pairs

t

completed

a

in

measurement

dieren-

optical

measuremen

elengths.

v

wa

ts,

t

2-14

Making

Measurements

Using The Cursor

PMD Measurement: Jones Matrix Eigenanalysis Method

Figure 2-18. The Cursor Bar

Changing

The Measurement

Maximize the PMD:JME window within the HP 8509B graphs

window. Activate the

NNNNNNNNNNNNNNNNNNNNNNN

Cursor

between the

Annotation

from the Graphs window menu. The cursor bar appears

Measurement Summary Bar

area. The cursor display shows the DGD value for a

Cursor Bar

by selecting

NNNNNNNNNNNNNNNNNNNNNNN

Display

and the

and then

Measurement

selected wavelength. The wavelength is selected by the slider control,

then

and

Alt

displa

the

.

y

arro

the

w

arro

keys

w

(The

keys),

keyb

or b

oard is

y editing

activ

the w

ated

v

a

pressing

y

b

elength

Format

Figure 2-19. Changing the Measurement Format

Select

Format

from the Main Graphs windowmenu to access the

measurement formatting functions. The measurement graph may

NNNNNNNNNNNNNNNNNNNN

can

length. Cho

er

ter the length of the

NN

N

from the

picoseconds

or

formatted

e

b

expressed

N

NN

N

in

kilometer

per

N

NN

N

NN

N

Fiber Length...

ve just measured.

ber y

ou ha

either

N

ADDITIONAL INFORMA

ro

er

p

N

Format

TION

or

ot

N

NN

N

toseconds. It

fem

kilometer

N

menutoen

of

b

b

also

If the ber is long enough to exhibit strong p olarization

mode coupling, you may wish to express the result in units of time

length

ot

ro

per

listed,

are

measuremen

and all

summary

t

using

alues

v

NNNNNNNNNNNNNNNNNNNN

Format

are

bar.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Delay/sqrt(L)

the

up

dated,

on

Making

new

The

.

Y-axis

and

Measurements

units

in

the

e

ose

2-15

PMD Measurement: Jones Matrix Eigenanalysis Method

Changing The Graph's Y-Scale

Figure 2-20. Changing the Graph's Y-Scale

Tochange the vertical axis on the measurement graph, select

NNNNNNNNNNNNNNNNNNNNNNN

Display

The submenuprovides three selections. The default selection,

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

and then

Autoscale/Zero

uses zero

but

oth

optimizes

the

selection

zero

b

measurement

allows

minim

the

as

NNNNNNNNNNNNNNNNNNNNNNN

Y-Scale

Based

the

minimum

minim

as the

curv

specication

v

um

to

e

alue.

,

um and

from the Graphs main window menu.

autoscales

value.

maximum

graph

the

ll

the

of

the

The

area.

maxim

um

NN

N

Autoscale

Y-axis

The

Y-axis

um

NN

Y-axis

N

NN

v

N

Fixed

N

selection

alues

N

NN

N

alue

v

to

N

Scale ...

alue

expand

N

and

N

uses

N

NN

N

Displa

ying

and

Printing

abular

T

Data

in

Display the tabular measuremen

then

bo

text bo

NNNNNNNNNNNNNNNNNNNNNNNNN

NNNNNN

Tabular Data

x lls the Graphs windo

x lists information from the measuremen

Format

Figure

ying

Displa

2-21.

NNNNNNN

tdatab

from the Graphs main

verlaying

w, o

abular Format

T

in

Data

NN

N

y selecting

N

Display

window men

the measurement graph. The

t annotation area,

the values in the measurement summary,andalistofwavelengths

at which optical measurements were performed along with the

DGD values derived from each pair. The

en.

op

is

x

o

text b

the

disabled

when

4

Start Measurement

N

and

u. A text

5

button is

2-16

Making

Measurements

PMD Measurement: Jones Matrix Eigenanalysis Method

ADDITIONAL INFORMATION

You can add your own notes to the text. All of the stan-

dard keyboard and mouse editing features are available. Use the

mouse to place a text insertion pointanywhere in the document,

and then type the desired text. Text may be selected using the

drag features of the mouse. Selected text may be deleted or copied

to the clipb oard for use in a report or a spreadsheet by pushing the

4

Copy to clipboard

5

button.

The tabular data text box is limited to 60,000 characters.

All or a p ortion of the text box information may be printed. Printing

uses the default printer selected in the windows control panel. To

print all of the text box information just press the

4

Print tabulardata

5

button at the top of the text box. Toprint a portion of the text b ox

information, hi-light the desired text with the mouse before pressing

the

4

Print tabulardata

4

the

Return

N

NN

N

Display

N

to

men

graph

u.

5

button. To return to the graphic display, press

re-select

button

5

or

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Tabular

Data

under

the

Displa

ying

Data

in

a

Statistical

Data

format

for

After making y

in the PMD:JME measuremen

results in a statistical format b

NNNNNNNNNNNNNN

PMD Statistics

Format

from

using

discussion

a

NNNNNNNNNNNNNNNNNNNNNNNNN

PMD

its

2-22.

measuremen

Statistics

application

ying Data

Displa

PMD:JME

the

of

Figure

our PMD:JME measuremen

twindo

NNNNN

y rst selecting

. A PMD Statistics windo

can

ts

feature.

er

(Fib

in

w, y

ed

y

displa

e

b

Concepts

the

See

Statistics).

PMD

Statistical

a

t, and while still

y displa

ou ma

NNNNNNNNNNNNNNNNNNNNNNN

Display

w will open.

statistical

in

Format

y the

and then

section

Making

Measurements

2-17

PMD Measurement: Jones Matrix Eigenanalysis Method

Figure

Maxw

N

or

PMD

N

from

N

Add

A

multiple

N

NN

N

Selected

N

NN

N

from

Statistics

N

window.

Single

the

in

N

NN

N

Add

and

ADDITIONAL

Displa

2-23.

illustration

curv

ell

PMD:JME

windo

N

NN

N

NN

N

Text

INF

JME

N

File...F4

ORMA

e

N

ying

an

is

w.

N

Window

N

NN

N

TION

a Statistical

in

Data

example of

automatically

measuremen

com

y

an

Use

N

NN

N

to

N

,

F2

ort

imp

the PMD

tted

can

ts

bination

N

NN

N

from

Add

data.

Format

statistics

the

to

displa

e

b

of

N

NN

N

Database...F3

histogram.

ed

y

NN

N

The PMD Statistics function can be selected in twoways;

from the PMD:JME measurement window, or by double clicking

on the PMD Statistics icon in the HP 8509 Program Group in the

Program Manager. The PMD Statistics function is actually provided

by a separate software application.

N

,

2-18

Making

Measurements

PMD Measurement: Jones Matrix Eigenanalysis Method

Figure

menu

File

The

N

NN

a

ts

N

from

windo

v

a

W

are used

N

from

N

NN

N

in

NN

men

of

NN

N

elength

NN

N

titled

N

NN

N

a

from

File

structure.

u

File

the

N

Selected

will

w

graph.

to

and

w.

windo

N

NN

Database...F3

\Load:

stored

N

NN

N

ys and opens a windo

w.

NNNNNNNNNNNNNNNNNNNNNNNNN

le

text

a

with

b

ts

poin

Selecting

wn

do

elemen

N

Add

JME

the

graph

Histogram

Statistics

N

NN

Add

PMD Statistics Database Interface window to open. You can then

load the measurement results from a previously stored measurement

into the PMD Statistics window.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Add from Text File...F4.Selecting this menu item will cause a

window

previously

N

Load Statistics...F5

Statistics displa

can then load previously stored PMD statistics data

Statistics windo

NNNNNNNNNNNNNNNNNNNNNNNNN

NN

Save Statistics...F6.Selecting this menu item opens a window

titled \Save: Text File". You can then save the current statistical

data

analysis

or

including

2-24.

main

the

The

u.

men

N

NN

N

JME

wn

sho

e

b

The individual

the

build

the

e

deriv

N

NN

N

ext

T

to

le

text

NN

N

NN

N

for

spreadsheet.

ey

NNNNNNNNNN

future

ond

.

the

Statistics

PMD

wing

follo

N

NN

N

Window

in

Cum

N

.

File"

Selecting this men

retriev

displa

F2

Dieren

the

ulativ

statistics

other

Selecting

op

to

ort in

imp

al

measuremen

All

ed

y

w titled \Load: T

to

Statistics

PMD

File Menu

windo

brief

a

is

data

The

.

Group

tial

measuremen

Dieren

e

listed

u

men

this

can

ou

Y

en.

PMD

the

to

u item clears the PMD

PMD

the

elength

v

a

w

will

w,

description

the

from

Delay

oin

p

t

Group

tial

the

in

will

item

then imp

Statistics

ext File". Y

into the PMD

Statistics

ts

oin

tp

range.

drop

of

current

v

of

ts

Dela

PMD

cause the

ose

windo

sa

are

the

ersus

this

y

a

ed,

v

w

w.

ou

Making

Measurements

2-19

PMD Measurement: Jones Matrix Eigenanalysis Method

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

N

Print Bitmap.Selecting this menu, will giveyou three choices. To

print the DGD versus Wavelength graph, the Histogram or the entire

window.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Print Data.Selecting this menuwillprint the data. Printing uses

the default printer selected in the windows control panel.

NNNNNNNNNNNNNN

Exit.Selecting this menu will quit the PMD Statistics window

The Edit menu

recently

the

a

W

N

NN

N

All

and

N

Bitmap

elength,

NNNNNNNNNNNNNN

Edit

from the main PMD Statistics window, will drop

added

statistical

elength

v

N

Data

N

cop

N

the

N

to

ying

Histogram

purges

NN

N

measuremen

data

N

Selecting

.

statistical

N

NN

N

Clipboard

to

Selecting

down a menu structure. The following is a brief description of the

elements of that Edit menu.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Undo Last Add Alt+Bksp

most

from

ersus

v

set.

N

Clear

data

N

NN

Copy

selections,

v

a

W

. Selecting this menu item removes the

t

This

set.

efore committing

b

this men

data

N

the

clipb

or

This

.

oard

the en

from

allo

set.

men

our

y

tire

the

y

ws

u item

u

hoice

c

PMD

statistics

examine

to

ou

the statistical

it to

remo

pro

item

of

Statistics

es

v

vides

DGD

displa

the

displa

all

three

v

windo

ys

ersus

and

DGD

data

ed

y

w.

2-20

Making

Measurements

Format

The

Selecting

down a menu structure. The following is a brief description of the

elements of that Format menu.

NN

N

NN

N

Wavelength

elength range

v

a

w

data poin

NNNNNNNNNNNNNNNNNNNNNNNNN

NNNN

Autorange

highest w

NNNNNNNNNNNNNNNNNNNNNNNNN

Fixed Range...

set the minim

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Histogram X-Axis

range of

the

N

NN

N

Autoscale

include

to

N

NN

N

Fixed

Menu

NNNNNNNNNNNNNNNNNNNN

Format

N

NN

N

ts displa

avelengths of the added or loaded

NNNNNNNNNNNNNNNNNNN

N

all

NN

N

Scale...

from the main PMD Statistics window, will drop

N

NN

N

Range

adjusts the w

um and maximum

DGD

selected,

is

DGD

N

This

.

used

e

b

to

yed in this graph are included in the histogram.

avelength limits to include the lo

selection op ens a dialog bo

. This menuitemprovides twoways to select

to

alues

v

the

in

alues

v

N

selected,

is

men

in

e

b

X-axis

the

a

u

item

the

displayed w

displa

statistical

dialog

pro

DGD

ed

y

range

b

o

ys to

a

w

o

w

t

vides

elength graph.

v

a

W

vs

JME PMD data. The

ou

y

hy

adjusts

When

to

set

x with whic

avelengths.

histogram.

the

in

automatically

set.

data

enables

x

select

Only

west and

ou can

When

the

PMD Measurement: Jones Matrix Eigenanalysis Method

maximum value of DGD to be displayed. The minimum value is

always zero.

The Help menu

The Help menuonlyprovides information ab out the software revision

of the PMD Statistics software, which is a separate application.

The Annotation Area

At the bottom of the PMD Statistics window are a group of numeric

displays, which are describ ed below.

Mean

. This display shows the mean, or average, value of the data

points which are displayed in the DGD vs Wavelength graph. The

is

mean

Minim

um,

maxim

DGD vs

the

selection

um

not

Maxim

v

of

aected

alues

v

a

W

X-axis

the

y

b

.

um

DGD

of

elength

selection

These

of the

graph.

of

scale

of

displa

data p

These

the

X-axis scale

the

w

sho

ys

ts

oin

alues

v

histogram.

the

whic

are

of the

minim

are

h

not

histogram.

and

um

displa

aected

in

ed

y

b

DGD

of

er

b

um

n

the

ws

sho

y

displa

This

t

The

and is

This

.

data

um

n

not

displa

the

oin

p

er

b

aected

ys.

y

DGD

ts

ere

w

h

whic

indicates the

the

y

b

cum

the

ws

sho

v

a

W

ersus

v

added

size

hoice

c

ulativ

elength

of

with

the

X-axis

size

e

graph

last

the

original

limits

the

of

in

is

add

measuremen

either

of

statistical

the

added

le

Last

measuremen

eration.

op

data set,

graphical

the

size

otal

T

data set

when

Wavelength Range / Auto Range mo de.

Subset size

. This display replaces the Total size display when the

DGD versus Wavelength graph is placed in the Fixed Range mo de.

This parameter indicates the number of DGD measurementdata

whic

y

range is

range.

sho

h

the

ws

divided

umb

n

for

ts

oin

p

b

Num

categories

of

that

er

of

fall within

This is

.

bins

k

buc

or

ets

the

in

displa

an

to

ed

y

editable

h

whic

w

displa

the

elength

v

a

DGD

construction of the DGD Histogram.

of the single

Maxwell alpha parameter

parameter

which species the Maxwell curv

. This displa

ws the v

ysho

e that is automatically

alue

tted to the DGD histogram.

t

of

er

Making

Measurements

2-21

PMD Measurement: Jones Matrix Eigenanalysis Method

Printing the PMD:JME Graph

Figure 2-25. Printing the PMD:JME Graph

Sa

ving

Measurement

our

y

Select

Selecting

annotation

Area."

Selecting

annotation

the

ext

T

as

NNNNNNNNNNNNNN

File

and then

NNNNNNNNNNNNNNNNN

Graph

will print only the graph.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Graph & Annotation

information

N

Graph,

Annotation, &

N

NN

N

information and

corresp

onding

data

NNNNNNNNNNNNNNNNN

Print

N

from the Graphs main window.

will print the graph and the

Measuremen

\The

N

list the

ts.

in

N

NN

N

Data

measuremen

N

will

prin

discussed

N

NN

N

oin

p

t

the

t

a

w

Annotation

t

graph,

elengths

v

and

2-22

Making

Measurements

Figure

Select

N

File

and

then

N

Save

N

NN

N

window. A standard windo

ou can select a le name and a directory in whic

ty

poin

will b e stored. Columns of w

will b e sa

ved as text for later use in a spreadsheet. Data sa

2-26.

N

from the

Text

as

JME

w

screen will be displa

Save

Graphs

yed. A

N

NN

N

NN

N

NN

N

NN

N

h the data

elengths and measuremen

av

ext

as T

e

v

Sa

text cannot b e recalled for future displayby the analyzer.

main

tthis

t data poin

ved as

ts

Saving in Database Format

PMD Measurement: Jones Matrix Eigenanalysis Method

Figure 2-27. Saving in Database Format

Select

NNNNNNNNNNNNNN

File

and then

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Save JME to Database...

from the Graphs

main windowtosavetheentire measurement and annotation

for future analysis using a database program or to reload the

measurement and certain setup parameters backinto the analyzer. A

of

up

made

is

title

default

measuremen

the

ou

but y

a

ter

en

title

ma

serial

for

y

the

t

wish

um

n

measuremen

and

e

yp

t

it

edit

to

date

and

er

b

the

for

is

t

date

our

y

de

co

pro

and

o

for

vided.

wn

The

time.

the

It

oses.

purp

device under

is

unique

a

ou

Y

ma

test.

name,

y also

Making

Measurements

2-23

PMD Measurement: Jones Matrix Eigenanalysis Method

Specialized Measurement Methods

Performing a Cascade Measurement

Cascading is a measurement procedure that mathematically increases

the accuracy of p olarization mo de dispersion (PMD) measurements

of devices and components that can't be directly connected to

the HP 8509B Optical Output without using additional optical

interfacing. PMD cascading techniques are used in bulk optical

applications to separate the PMD response of the test device from

the cloaking eects of the combined PMD response of the xtures

and adapters between the HP 8509B Optical Output and the input

to the test device. Fib er optical applications b enet as well because

the response of optical source interfacing isolators, connectors and

cables of the test system (represented by DCO in the gure shown

below) can be mathematically removed from the total PMD response,

leaving behind the response of the targeted test device (DUT in the

w).

the

of

source

belo

test

terfacing

in

greater

device

than

gure

resp

shown

onse

optical

individually

This

hnique

tec

(DUT)

(DCC)

100 fs.

are

and

most

is

the

appro

eectiv

undesired

ximately

when

e

PMD

the

same

the

of

PMD

the

and

2-24

Making

Measurements

Figure

2-28.

Setting up the System

the Optical

Attach the device to be calibrated out (DCO), bet

Output and the

following illustration. T

Optical Input of the HP 8509B, as outlined in the

ape do

wn the pigtails so that only the nal

ween

portion of the output pigtail of the DCO will b e allowed to move

when the nal test device (DUT) is inserted. Movement of the

calibration

the

een

w

et

error.

t

b

mo

DCO,

or

measuremen

emen

v

t,

tof

causes

pigtail,

input

its

measuremen

and

PMD Measurement: Jones Matrix Eigenanalysis Method

Figure 2-29. Measurement Setup

Making the Measurement

Prepare the

1.

polarization

Source

2.

Select

then

N

PMD:

external source

follo

y

b

Preparation

Measurement

N

NN

N

NN

N

NN

N

Jones

wing

p

N

Matrix

to pro

pro

the

this

ortion

from

N

of

main

the

N

NN

N

Eigenanalysis...

vide a

cedure

JME

windo

N

NN

N

circular

describ

PMD

w

N

men

N

state

the

in

ed

section.

selections, and

u

N

NN

N

.

F2

of

External

N

ts,

N

NN

then

Figure

source

then

N

from

N

Cascaded

select

N

2-30.

Set

3.

um

n

4.

Select

selections,

optical

the

up

oin

p

of

er

b

N

Measurement

and

5. Note that the measuremen

ellow

ration

w, a y

5or4

New Thru Cal

graphs windo

4

Start Calib

right portion of the graph windo

the

for

4

Done

graphs

the

N

NN

N

Measurement

trol area at the bottom of the

tcon

NNNNNNNNNNNNNNNN

NNNNNNN

Cascade

5

, whic

w

range

men

desired

.

5

N

Device

main

NN

N

NN

w

N

.

elength

v

a

windo

Start

banner appears. Select

hever appears at the bottom

w.

the

and

u

Making

Measurements

2-25

PMD Measurement: Jones Matrix Eigenanalysis Method

The

6.

DCO.

calibration

only

resulting

When

ma

ber

the

if

Figure 2-31.

measuremen

calibration

thru

the

redone

e

b

y

the

or

DCO

Thru Calibration

haracterizes

c

t

is

selecting

y

b

mo

has

complete,

v

Figure 2-32. The Measurement

ed

PMD

4

New

during

Thru

eects

select

Cal.

the

of

4

Continue

.

5

erform

P

5

calibration.

.

The

this

2-26

Making

Measurements

7. Remo

ve the output pigtail of the DCO from the optical input

e only the output pigtail

of the HP 8509B, taking care to mo

v

and not the DCO or its input pigtail. Connect the device to be

measured (DUT) b etween the output pigtail of the DCO and the

Optical

Input of

the

olarization

p

analyzer.

PMD Measurement: Jones Matrix Eigenanalysis Method

8. Select

4

Start Measurement

5

. When the measurement is complete, the

PMD eects of the rst DCO are removed and the displayed DGD

represents the newly inserted device. Refer to the follo wing gure.

Results

The

Figure

2-33.

CA

UTION

PMD

general,

In

Single

duce

pro

the

Device

the

measuremen

ected DGD

exp

ADDITIONAL INF

cascaded

of

alues

v

of

ts

the

of

ORMATION

w

t

devices

o

same

devices

cannot

devices

not

do

b

cascade.

in

simply

e added

add.

to

The eectiveness of this method can be veried in two

ways.

1. Perform a cascade thru calibration on a device and then measure

path.

t

b

that

device

same

the

small v

ery

v

the

device

itself

The device m

ers. The

b

y

an

ving

alue

without

of

has

DGD,

een

b

mo

ypically

t

remo

under

ed from

v

0.010ps,

measuremen

the

ust be stable in temperature for this v

result

should

indicating

erication to

be meaningful.

2. Measure the DGD of a device (DUT) in the Single Device mode

(without a cascade thru calibration). Then p erform a cascaded

PMD measurement using this same device (DUT) connected to

a second device (DOC) that has b een cascaded out. The PMD

measuremen

obtained

imp

is

in

ortan

t

the

t.

result

Single

should

Device

be

ery

v

mode.

close

Again,

to

measuremen

the

erature

temp

t

stabilit

a

e

y

Making

Measurements

2-27

PMD Measurement: Jones Matrix Eigenanalysis Method

Using a Voltage-Tuned Source

The JME PMD measurementmay be performed using a voltage

tuned optical source. Operation is automatic once the measurement

is started. To p erform a measurementwithavoltage-tuned source,

open a JME PMD window and select Optical Source Setup. Use

Optical Source Selection to choose the voltage-tuned mo de. You will

see a change in the information displayed in the Wavelength area

of the window. Enter the wavelength parameters and number of

points as you would for an HP-IB source. Enter the tuning voltages

corresponding to the start and stop wavelengths. This \calibrates"

your wavelength tuning and requires knowledge of the source tuning

characteristic. The tuning voltage is programmed in linear fashion

between the entered limits. Set the settling times as required for

your source, or use the default values. Connect the tuning voltage

connector

BNC

from

Close

oltage-tuned

v

measuremen

the

laser.

t.

\A"

on

the

rear

the

Optical

panel

Source

of

the

Setup

8509

form

to

the

and

start

Using

Manually-Tuned

a

source

PMD

JME

The

tuned

line

optical

laser

sources

measuremen

Optical

select

manually

the

longer relev

measuremen

source.

with

t

Source

tuned mo

and

t

an

that

a

are

This

lac

man

Setup.

de. The

gra

feature

hardw

k

ual

ed

y

b

may

t

enables

are

source,

Optical

Use

settling time

En

out.

erformed

p

e

tuning

en

op

ter

y

a JME

Source

the

using

use

to

ou

terfaces.

in

PMD windo

Selection

parameters

elength

v

a

w

tunable

p

o

T

to

are

parameters

single

erform

w

hoose

c

no

ually

man

a

and number of points as you would for an HP-IB source. Close

the Optical Source Setup form and start the measurement. The

instruction window will prompt you to adjust the wavelength of the

source and take the next p oint. Repeat this until the measurementis

complete.

a

and

2-28

Making

Measurements

PMD:JME Concepts

Polarization Mode Dispersion

Polarization modes

PMD is a fundamental property of optical ber and components by

whichanylightwave signal is split into two polarization modes that

travel at dierent speeds. In eect, single mo de ber is bimo dal with

respect to polarization. The dierence in propagation time between

the two polarization modes is called dierential group delay.

General effects

Because

the

distinction

source

v

c

a

time and

in

v

cable-television

of

olarization

p

may

dieren

of

alues

com

in

hirp

transmitted

signal

system,

the

ariation.

PMD Measurement: Jones Matrix Eigenanalysis Method

of

h

eac

to

from a

inuence

the

as

erted

v

in

degrading

spectrally

laser

can

path

function

a

is

loss

t

amplitude

to

distortion

of

frequency

cause

presen

PMD,

w

et

b

become

bination

signal

the

This

ligh

des

mo

pulses.

een

partly

tial

tensit

in

olarization

p

eect

a

w

t

broaden

group

with

ary

v

to

.

y

causes

pulses

e

v

as

In addition,

olarized

dep

.

y

dela

in

PMD

polarization

in

olarization-dep

p

If

ariation

v

comp

hed

launc

propagate,

they

light

under

Finally

,

transmission

a

is

second-order

osite

partly

transmitter

state

enden

con

systems.

the

wide

large

of

t

in

Mode

Mo

coupling

de-coupling

optical

coupling

the

to

en

giv

term

the

is

of

energy

between polarization modes along the transmission path. Two-port

optical devices (including optical ber) fall into two categories

according to the degree of mode coupling. Non-mode-coupled devices

include most comp onents, hi-bi (polarization maintaining) ber and

short lengths of ordinary single-mo de ber. For these devices, energy

remains

de

olarization

p

each

to

in

hed

launc

propagates.

is generally

dieren

The

independen

tial

tofw

mode coupling, is exhibited b

long b

ers, energy couples b et

mo

y

group

dela

avelength. The other extreme, strong

y long lengths of single-mo de ber. F

ween mo des due to ph

internal to the ber and optical eects induced b

environment.

The dierential group dela

in

non-mo

of

de-coupled

ysical v

devices

ariations

y the ber's

y of highly mode-coupled

or

it

as

de

mo

that

devices is a strong function of wavelength. An intermediate degree of

mode coupling, typical of short to medium lengths of optical ber,

function

eak

w

ely

relativ

a

is

h

whic

y

results

a

w

of

dieren

in

elength.

v

tial

group

dela

Making

Measurements

2-29

PMD Measurement: Jones Matrix Eigenanalysis Method

PMD units

Fiber PMD statistics

Dierential group delay is expressed in units of time, generally

either picoseconds (1 ps = 10

12

s) or femtosecond (1 fs = 10

0

15

s).

0

Short-ber PMD may be expressed in terms of time per meter or

kilometer. Due to the eects of mo de-coupling, long-b er dierential

group delay increases as the square ro ot of ber length. Therefore,

long-ber dierential group delay is often expressed in terms of time

per square root of ber length (in kilometers).

The \PMD" of a component or ber is simply the average dierential

group delay.For non-mo de-coupled devices, this may b e obtained

from a single pair of Jones matrix measurements separated bya

known wavelength interval, although in practice an average of several

intervals is used. For highly mode-coupled devices, the measurement

is repeated at a manywavelength intervals across a large wavelength

range. The average dierential group delay is simply the average of

these individual values.

Fitting

T

sucien

the individual

a

curv

closely

dela

the

determine

o

est-t

b

represen

e

resem

tak

y

tly

Maxw

en

whether

sampled

dieren

ell

the

ts

the

bles

the

from

elength

v

a

w

the

particular measuremen

a

in

group

tial

probabilit

ected

exp

Maxwell

measuremen

dela

distribution

y

shap

curv

t

e

e,

can

y

for

the

dep

v

endence

ma

alues

function.

bers.

long

erage

v

a

considered

e

b

of

t, a

e

b

y

dieren

er has

ab

histogram

compared

Maxw

The

data

the

If

tial

statistically

b

of

to

ell

group

een

distribution

the

to

e

curv

ell

Maxw

accurate.

The HP

8509B soft

eigenanalysis

hi-squared

c

w

measuremen

to

d

metho

pro

are

generate

vides

results

t

statistical

a

for

b

the

this

est-t

displa

ose.

purp

Maxwell

uses

It

curve.

the

matrix

Jones

of

y

Once the Maxwell curve t has been performed, the quality of the t

to the data must b e determined. This may b e done qualitatively,by

visually assessing the t, or by use of the quality of t parameter

displayed in the statistics window.

sample

Enlarging

the

If

the

quality

of

the ber. This is most easily accomplished b

wavelength range of the measuremen

measurements should be tak

as p ossible, with w

size

or,

o

p

is

t

avelength in

more

data

required

is

to fully

y expanding

, long-b er PMD

awavelength range

ver as wide

en o

t. Generally

terval small enough to capture the

represen

the

t

features of the curve of dierential group delayversus wavelength.

However, for some bers even the full wavelength range may not b e

sucient to produce a distribution of Maxwellian shape. In such

measuremen

of

the

temp

the

de-coupling

mo

erature.

analysis.

for

All

sample

cases,

at

c

of

the

dieren

t

haracteristics

resulting

the

temp

of

size can

eratures,

b

the

is

data

er

com

increased

e

b

based

are

bined

on

strong

in

y

b

fact

the

functions

a single

eating

rep

that

histogram

t

2-30

Making

Measurements

If the ber temperature is changing naturally,duetochanges in the

ambient temperature, the measurementmay be rep eated versus time

to enlarge the sample size. If the b er is in cable form, temperature

change may be induced by passing a current through the metal

members of the cable. The sample size for spo oled b er can also be

enlarged by rearranging the turns of ber on the spo ol. For example,

a sp ool of loosely coiled ber can be turned end over end between

measurements.

Source spectral characteristics

The Jones matrix eigenanalysis method of PMD measurement

involves measuring the output state of p olarization of the device

under test with various linear polarizers inserted in the path b etween

optical source and the device. This requires that the output of

the test device always be at least partially polarized. The output

will dep olarize if the coherence time of the source approaches the

dierential group delay of the test device. Single-line lasers of narrow

ectral

sp

recommended

metho

d.

PMD Measurement: Jones Matrix Eigenanalysis Method

Source,

width,

for

suc

h

the

as

Jones

8168A

HP

matrix

unable

T

eigenanalysis

Laser

PMD

measuremen

are

t

Should

Cascade

reference

the

use

I

measurements

frame?

reference

The

birefringence

or

the

from

olarization

p

elength

v

a

w

the

preformed

should

not

test

across

be

frame

and

path

receiv

at

used.

feature

olarization

p

etw

b

The

er.

whic

a

w

a

een

it

h

elength

v

remo

dep

automatic

the

reference

up.

set

is

range,

birefringence

es

t

enden

p

frame

is

Since

reference frame

the

olarizer

PMD

(2-p

oin

(3-p

loss

and

appropriate

measuremen

method)

t

the

only

feature

ts

to

are

d)

metho

t

oin

What is a cascade measurement?

A cascade measurement measures the DGD of a single test device

while that test device is connected in series with other elements that

measuremen

demonstrate

DGD.

PMD:JME measuremen

The

ts

of

test device installed. This allo

remove the dieren

tial group dela

a

ws the

t

through

path

HP 8509B to mathematically

y of the path bet

without

and

with

ween the polarizer

the

olving

v

in

cess

pro

step

o

tw

a

is

and the test device.

Typical applications

The cascade metho d is not used in ordinary PMD measurements

in which the device under test is connected by pigtails to the front

ery

v

the

ving

remo

panel

small

y

ma

the

of

amoun

used

e

b

instrumen

dieren

of

t

cases

in

as

t,

tial

where

is

it

group

an

capable

not

dela

optical

of

pigtails.

the

of

y

device with

Making

ev

w

Ho

signican

t

Measurements

er,

PMD,

it

2-31

PMD Measurement: Jones Matrix Eigenanalysis Method

such as an isolator, is placed b etween the instrument and the input of

the device under test.

The cascade measurementmay also be used to test individual

sections of a telecommunications system mo del or test bed. Such

systems consist of many sections, each of whichismadeup ofoneor

more amplier/ber pairs. Such systems may provide measurement

taps between sections. The PMD of individual sections maybe

measured using these taps, without disturbing the through path

connections. The output pigtail of the polarization analyzer is

connected to the input of the system and left there throughout the

measurement. A cascade reference measurementistaken with the

optical input of the polarization analyzer connected to the tap just

prior to the section of interest. Then the section of interest is added

and the second step of the measurement is performed. The resulting

measurementcharacterizes only the selected section. If the goal of

the PMD measurement is to relate the PMD of individual sections

to the PMD of the whole system, the cascade measurementmaybe

repeated on each of the sections to characterize the sections. Ateach

PMD

osite

comp

stage,

cascade

v

ro

the

reference

y

ma

one

alues,

ot-sum-of-squares

measurement.

compare

exp

of

the

ected

preceding

all

With individual

addition

alue.

v

of

sections

PMD

is giv

and comp

the

with

ythe

en b

osite PMD

ected

exp

2-32

Making

Measurements

PMD Measurement: Wavelength-Scanning Method

Polarization mo de dispersion (PMD) is a fundamental physical

property of optical ber and components in which a lightwave is split

into twowaves of slightly dierent speed on the basis of polarization

state. The two polarization modes experience a dierence in

propagation time known as \dierential group delay" (DGD). The

DGD of long optical bers varies with wavelength. The \PMD" of a

test device also refers to the average value of the dierential group

delay. PMD is fundamentally expressed in units of time, typically

0

picoseconds (1 ps = 10

12

s), although in the case of long bers it

may be normalized to the square root of ber length with the units

of picoseconds per root kilometer.

This section explains how to measure the PMD of a test device using

the wavelength-scanning (WS) metho d. A typical measurement

result is shown in the following gure.

Figure 2-34.

measurement

Example

of

for

y

displa

data

Typical applications of the w

elength-scanning

v

a

w

a

elength-scanning method include

av

PMD

measurement of medium to long optical bers and cables. It can also

be applied to the measuremen

used to c

haracterize amplied systems in whic

t of some

large enough to pro duce a useable n

componen

h the lev

ber of peaks and v

um

ts, and ma

ybe

el of PMD is

alleys in

the response within the system passband. Consider the following

aspects of the wavelength-scanning method when deciding which

use:

to

is

erformed

p

e

d

sligh

tly

faster

with

than

the

Making

HP

JME

the

8509A

Measurements

metho

B.

or

d.

2-33

measuremen

PMD

Measuremen

metho

The

d

t

can

sp

t metho

eed

b

PMD Measurement: Wavelength-Scanning Method

The metho d provides more optical p ower to the DUT than the

JME metho d do es.

A single PMD value, or average dierential group delay,is

produced from measurement across a wavelength span.

Broad wavelength ranges are required for measurementoflow

PMD values.

The measurement is inuenced by pigtail position and polarization

launch condition, particularly for lowvalues of PMD.

Basic Measurement

System

the

Setting

up

The following measurement procedure illustrates the simplest and

most straightforward path in using the HP 8509A/B Lightwave

Polarization Analyzer operating system software to makea

wavelength-scanning PMD measurement.

Connect

measuremen

our

y

system

t

outlined

as

in

wing

follo

the

illustration.

2-34

Making

Measurements

elength-Scanning

v

a

W

signal

2-35.

applied to

is

olarization should be adjusted for

Figure

source

the

If

HP 8509B, External Source P

circular polarization as described

hapter.

this c

System

the

External

Source

in External Source Preparation in

Setup

Input

of

the

Connecting the tunable laser directly to the DUT extends the

amplitude range of the measurement to allow measurement of higher

loss devices. If the source is not p olarized, an external polarizer must

used.

e

b

Making the Measurement

UTION

CA

PMD Measurement: Wavelength-Scanning Method

At this pointyour measurement system is ready to makeyour

rst measurement. For our purposes we are going to measure a

ten kilometer length of ber. Connect your test device between

the optical output of the laser source and the optical input of the

analyzer.

ACCURACY ENHANCEMENT NOTE

The ber path leading from the tunable laser source to the

DUT and from the DUT to the 8509 optical input must not move

during the measurement process. Unsupported ber, particularly

unjacketed ber, should be taped down or placed against stationary

ob jects. Movement of the ber may jeopardize PMD measurement

accuracy.

ve

a

w

t

\Ligh

the

to

Observ

e

Connector

prop

Care"

connection

er

hapter

c

tec

in

hniques.

man

this

Refer

ual.

Figure 2-36. Wavelength-Scanning Measurement Selection

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Select

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

PMD:Wavelength

Measurement

Scanning...

from the main menu, and then select

Shift+F2

Making

Measurements

2-35

PMD Measurement: Wavelength-Scanning Method

Figure 2-37. Optical Source Setup for PMD:Wavelength Scanning

Verify that the source and wavelength are correct for your

measurement, and that the power is on. If the screen on your

computer lo oks like the previous illustration, select

4

Done

5

.

ADDITIONAL INF

broader

A

measuremen

accurate measuremen

main

to

wish

ou

y

If

o

p

the

to

in

ter

en

alue

v

a

w,

windo

of

y

displa

lasers

er

b

nm.

bers,

de

e

b

y

ma

,

bers

de

are

Single-mo

generally

1

of

Single-mo

PMD

ORMA

t

t.

lev

tain

el

lev

er

w

greater than

no

ailable

v

a

lengths

adequately

that are

measured

est

b

TION

elength range

v

a

w

p

eled

y

displa

p

laser

range

the

in

measured

h longer

muc

with

w

o

of the

the

er.

w

o

during

er

minim

of

a

w

produces

optical

um

10

using a

y

b

than

elength

v

measuremen

the

source

w

o

p

or

km

10

deltas

a

er

lo

wa

more

setup

sho

PMD

w

elength

v

ha

or

of

wn

v

0.25

e

t,

in

b

delta

high

nm

the

ers,

2-36

Making

Measurements

Select

WS

The

erformed

p

4

Sta

rt

graphs

Figure 2-38. PMD: WS Measurement Start

optical

of

range.

Graphs

Measurement

are

across

the

from

5

deriv

selected

ed

the

from

w

HP

a

elength

v

a

8509A/B

series

screen.

measuremen

the

As

ts

t

PMD Measurement: Wavelength-Scanning Method

progresses, the

Measurement Summary

display bar directly belowthe

graph lists the PMD results obtained, up to the currentwavelength.

ACCURACY ENHANCEMENT NOTE

If your wavelength range was not sucienttoprovide at

least two peaks in one or more of the measurement curves, you will

get the message \One or more of the wavelength scanning traces has

an insucientnumber of p eaks." If you choose

4OK5

and continue

with the measurement, the measurement will ignore these curves and

derive PMD from the curves whichdoshow at least two peaks.

Figure

Measurement

2-39.

Results

Your measurement is complete. The screen on your computer should

look similar to the previous illustration.

The three graphs have xed Y-axes of +1 to01 and showthe

measured values of the normalized Stokes parameters s1, s2, and s3.

graphs.

these

PMD

is determined

from

analysis

of

Making

Measurements

2-37

PMD Measurement: Wavelength-Scanning Method

Manipulating the Measurement Results

When your measurement is complete, you may;

Select one of the measurement curves to enlarge vertically.

Measurement

The

Review the results in the

Review the measurement setup conditions in the

Annotation

Examine a curve at a particular wavelength, by using the cursor

bar.

Display, edit, and print the data in tabular form.

Print the graph with or without measurement annotation and data

listing.

Saveyour measurement and annotation information to a database

for future use or to reload the measurement backinto the

HP

erform

P

Displa

or

Summary Bar

8509A/B.

other

all

y

cascade

area.

measuremen

your

of

de.

mo

Measurement Summary

without

ts

measurements

in

lea

one

ving

windo

bar.

Measurement

Graphs

the

using

w,

windo

either

w.

tile

2-38

Making

Measurements

Figure 2-40. The Measurement Summary

The

Measurement Summary Bar

up to the

currentw

avelength.

displays the PMD results obtained

All of the displays have the same units, which are user selectable but

default to picoseconds. The bar displays the PMD derived from each

erage.

v

a

their

as

ell

w

of

the

measured

Stok

parameters,

es

as

The Measurement Annotation Area

When the measurement ends, the control panel at the b ottom of the

Graphs window is replaced bythe

This area lists the date and time of the start of the measurement, the

ber length in kilometers, the tunable laser power and attenuator

settings, the

lists

also

optical

h

whic

eaks

p

of

annotation area

the

erformed

p

de

mo

the

detail

in

Minim

um

toggled

and

u,

men

PMD Measurement: Wavelength-Scanning Method

Figure 2-41. The Measurement Annotation Area

Measurement Annotation Area

step

the

iden

on

coupling

the

in

eature

F

and

on

then

start and

of

er

b

um

n

measuremen

each

in

tied

an

is

traces

the

factor

Concepts

Size.

o

N

NN

N

selecting

y

b

Annotation

elengths

p

oin

ts

ts,

w

av

that

ere

stop w

of the

whic

icon

the

and

also

is

k

section under

measuremen

N

The

N

Display

N

.

tak

curv

minim

N

NN

N

is,

en.

es.

indicates

h

wn.

sho

N

and

um

n

the

table

A

the

t

A

feature

um

These

title

the

annotation

t

N

from

er

b

lists

righ

the

topics

Analysis

the

v

a

w

av

of w

the

hand

t

of

e

yp

t

The

size.

are discussed

area

windo

main

.

elength.

elengths at

ber

num

of

edge

analysis

alue

v

and

de

Mo

e

b

can

w

It

of

Using

The Cursor

Figure 2-42. The Cursor Bar

Use the arrow button in one of the graphs to expand the

graph. Activ

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Cursor Bar

the

een

w

et

b

Annotation

parameters

slider con

the

ate the

Cursor Bar

from the Graphs window menu. The cursor bar appears

Summary

Measuremen

The

area.

selected

a

for

arro

trol,

t

cursor

w

eys,

k

w

a

y selecting

b

Bar

sho

y

displa

elength. The

v

editing

y

b

or

ws

NNNNN

Display

the

and

the

v

a

w

the

Making

NNNNNNNNNNNNNNNNNN

and then

Measuremen

normalized

elength

v

a

is

elength

w

Measurements

t

stok

selected

displa

es

y

b

.

y

2-39

PMD Measurement: Wavelength-Scanning Method

Changing The Measurement Format

Figure 2-43. Changing the Measurement Format

Select

measuremen

see

NNNNNNNNNNNNNNNNNNNN

Format

section

the

N

Delay

displa

e

b

to

N

Delay/L

to

,

Bar

N

Delay/sqrt(L)

Summary

length.

er

b

N

NN

N

Fiber

the b

N

position of the

average, median, or maximum value of PMD derived from the

three graphs s1, s2, and s3.

NNNNNNNNNNNNNNNNNNNNNNNNNN

whic

instrumen

valleys), and to use the endpoin

wa

appropriate). F

the PMD:WS

er y

N

NN

N

Avg/Median/Max Delay

Analysis

the

h

velengths of the rst and last feature (peak or peak/v

NNNNNNNNNNNNNNNNN

Extrema/Full Scan

peaks and valleys and to use the endpoints of the wavelength

scan

N

Extrema/First

oth

b

from the Graphs windowmenu to access the

discussion

a

or

formatting

t

y

b

Causes

N

b

N

NN

N

Length...

N

in

NN

N

p

the

in

ed

y

Causes

display

e

N

to

,

Bar

N

NN

N

v

ha

ou

N

NN

N

Measurement Summary Bar

This

elength-scanning

v

a

w

be

can

t

or a detailed discussion of the Analysis mo des, see

Concepts section with that title.

NNNNNNNNNNNNNNNNNNNNNNNNN

a

w

the

N

and

eaks

functions.

in

title

that

alues in

v

PMD

picoseconds.

PMD

the

picoseconds

in

ed

N

Causes

b

N

e

N

men

elength-scanning

v

N

v

the

y

displa

e

men

This

measured.

just

N

NN

N

set

NNNNNNNNNNN

NN

The PMD value displayed in the left most

item

u

coun

to

Causes the HP 8509A/B to countboth

N

Last

to

alleys and

F

PMD:WS

the

in

alues

v

p

alues

v

PMD

in picoseconds

ed

selection

u

selection

ws

allo

onse

resp

eaks

p

t

ts of the w

N

form

Causes the

use

to

Concepts.

Measuremen

the

kilometer

er

in

lets

,maybechosen as the

of the

curv

extrema

or

av

ula.

HP

v

a

w

the

PMD

of

Summary

t

Summary

t

er

b

of

the

Measuremen

kilometer

ot

ro

er

p

the

ter

en

ou

y

metho

es are

elength range or the

8509A/B

elengths

analyzed.

eaks

(p

to

of

units,

length.

t

length

y

b

d

plus

alley as

coun

rst

the

Bar

The

t

,

of

2-40

Making

Measurements

PMD Measurement: Wavelength-Scanning Method

and last feature (peak or valley) in the wavelength-scanning

formula.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Peaks/Full Scan

Causes the HP 8509A/B to countonly

peaks and to use the endpoints of the wavelength scan in the

wavelength-scanning formula.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Peaks/First to Last

Causes the HP 8509A/B to countonly

peaks and to use the wavelengths of the rst and last (peak) in

the wavelength-scanning formula.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Minimum Feature Size..

The value entered here is the

amplitude change, in linear units, required between a feature and

both of its nearest neighbors in order to be recognized as a feature

(peak or valley). For more details, see the PMD:WS Concepts

section of the same title.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Mode Coupling Factor (k)...

The mode coupling factor must

be set according to the type of test device. See the PMD:WS

Concepts section of the same title for details

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Polarizer

selections

in the

only

olarizers

P

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

,

A

Polarizer

the

trol

con

HP 8509B.

details.

for

of

use

See the

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

,

B

Polarizer

ternal p

the in

PMD:WS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

,

C

Polarizer

No

olarizer and

Concepts

section

are a

These

ailable

v

titled

Displa

ying

and

Printing

Select

er

b

ma

ou

y

N

(

Format

up

are

appropriate

the

enough

long

is

wish

y

N

NN

N

Delay/sqrt(L)

dated,

N

on

N

to

N

NN

N

to

express

N

Y-axis of

the

units

exhibit

N

the

N

).

for

strong

result

The

the

measuremen

the

p

in units

new units

graph,

olarization

time

of

listed,

are

in

and

results.

t

mo

p

the

If

coupling,

de

ot

ro

er

all

and

measuremen

summary bar.

Data

in

abular

T

Format

Figure 2-44. Displaying Data in T

abular Format

NNNNNNNNNNNNNNNNNNNNNN

Display the tabular measuremen

then

NNNNNNNNNNNNNNNNNNNNNNNNN

NNNNNNNNNNN

Tabular Data

NN

from the Graphs main window menu. A text

t data b

y selecting

Display

box lls the Graphs window, overlaying the measurement graph. The

annotation

a

list

along

t

of

a

w

with

elengths

v

the

text

alues

v

whic

alues

v

x

o

b

in

optical

h

deriv

information

lists

measuremen

the

measuremen

from

ed

eac

from the

t

ts

pair.

h

summary

p

ere

w

measuremen

and

,

erformed

the

length

alues

v

N

and

area,

at

DGD

t

the

Making

Measurements

2-41

PMD Measurement: Wavelength-Scanning Method

ADDITIONAL INFORMATION

You can add your own notes to the text. All of the stan-

dard keyboard and mouse editing features are available. Use the

mouse to place a text insertion pointanywhere in the document, and

then type the desired text. Text may be selected using the drag

features of the mouse. Selected text may be deleted or copied to the

clipboard by pushing the

The tabular data text box is limited to 60,000 characters.

All or a portion of the text box information maybeprinted. Printing

uses the default printer selected in the Windows Control Panel.

Toprint all of the text b ox information just press

on the Graphs window area. Toprint a portion of the text

box information, select the desired text with the mouse before

pressing

4

Return to Graph

under

4

Print tabulardata

5

at the top of the window or re-select

N

NN

the

Display

4

Copy to clipboard

5

.To return to the graphic display, select

N

men

u.

5

button.

4

Print tabular data

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Tabular Data

5

Printing

y

our

Graph

our

Select

N

NN

N

File

Printing

Figure

N

and

then

2-45.

N

NN

N

Print

NN

N

PMD

N

from

y

the

Graphs

main

windo

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Selecting

Graphs S1, S2, S3

will print only the graph.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Selecting

Graph & Annotation

will print the graph and the

annotation information discussed in \The Measurement Annotation

Area."

N

NN

N

NN

N

NN

N

NN

N

NN

N

NN

Selecting

annotation information and

the corresp onding data poin

N

Graph,

Annotation, &

list the measuremen

ts.

Data

will

graph,

the

t

prin

twavelengths and

w.

2-42

Making

Measurements

Saving your Measurement as Text

PMD Measurement: Wavelength-Scanning Method

Figure 2-46. SaveasText

Sa

ving

Database

in

Format

Select

File

and then

window. A standard window

NNNNNNNNNNNNNN

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Save WS as Text

Save

screen will be displayed. At this

from the Graphs main

pointyou can select a le name and a directory for the data to be

stored. Columns of wavelengths and measurement data points will b e

saved as text for later use in a spreadsheet.

data sa

The

instrumen

future

ved

as text

cannot b

recalled

e

for

t.

displa

the

y

b

y

Figure 2-47. Saving in Database Format

Select

NNNNNNNNNNNNNN

File

and then

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Save WS to Database...

from the Graphs

main windowtosavetheentire measurement and annotation

for

future

analysis

measuremen

t

and

using a

certain

database

setup

default title for the measuremen

type and the date and time. It is a unique name,

the measuremen

ou ma

but y

t

y wish to edit it for y

program

parameters

t is pro

our o

vided. The title is made up of

wn purp oses.

to

or

the analyzer.

to

in

reload

the

A

Making

Measurements

2-43

PMD Measurement: Wavelength-Scanning Method

PMD:WS Concepts

Polarization Mode Dispersion

Polarization modes

PMD is a fundamental property of optical ber and components by

whichany lightwave signal is split into two polarization modes that

travel at dierent speeds. In eect, single mo de ber is bimo dal with

respect to polarization. The dierence in propagation time between

the two polarization modes is called dierential group delay.

General effects

Because of PMD, lightwave pulses launched partly into eachof

the polarization modes broaden as they propagate, degrading the

w

et

ma

dieren

of

com

in

and

system,

b

ecome

b

y

bination

signal

This

signal

the

distinction

source

alues

v

hirp

c

a transmitted

time

the

in

ariation.

v

cable-television

pulses.

een

partly

group

tial

with PMD

to

tensit

in

olarization

p

causes comp

eect

systems.

v

y

ary

.

In

dep

dela

If

addition,

olarized

Finally

.

y

in a

olarization

p

in

olarization

p

ariation

v

osite

from

t

ligh

under

the inuence

transmitter

,

transmission

state

enden

dep

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Agilent 8509B Users Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Getting Started

Making Measurements