analysis and measurement fiber optic fault by using optical time domain reflectrometer (otdr)

ANALYSIS AND MEASUREMENT FIBER OPTIC FAULT BY USING

OPTICAL TIME DOMAIN REFLECTROMETER (OTDR)

AKWANIZAM BIN AZMI

This Report Is Submitted in Partial Fulfillment of the Requirements for the

award of Bachelor of Electronic Engineering (Telecommunication Electronics)

With Honours

Faculty of Electronic Engineering and Computer Engineering

Universiti Teknikal Malaysia Melaka

30 April 2009

ii

UNIVERSTI TEKNIKAL MALAYSIA MELAKA FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER

�

BORANG PENGESAHAN STATUS LAPORAN

PROJEK SARJANA MUDA II

Tajuk Projek :

ANALYSIS AND MEASUREMENT FIBER OPTIC FAULT

BY USING OPTICAL TIME DOMAIN REFLECTROMETER

(OTDR)

Sesi

Pengajian : 2005/09

Saya ………………………....AKWANIZAM BIN AZMI…………………………..…….. (HURUF BESAR)

mengaku membenarkan Laporan Projek Sarjana Muda ini disimpan di Perpustakaan dengan syarat-syarat kegunaan seperti berikut:

1. Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.

2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja.

3. Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan pertukaran antara institusi

pengajian tinggi.

4. Sila tandakan ( � ) :

SULIT*

(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia seperti yang termaktub di dalam AKTA RAHSIA RASMI 1972)

TERHAD*

(Mengandungi maklumat terhad yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan)

TIDAK TERHAD

Disahkan oleh:

__________________________ ___________________________________ (TANDATANGAN PENULIS) (COP DAN TANDATANGAN PENYELIA)

Alamat : Lot 572 Kg. Air Merah, 86800, Mersing Johor

Darul Takzim

iii

“I declared that this thesis is the result of my own work except the ideas and

summaries which I have clarified their sources.”

Signature : ………………………………………

Writer : AKWANIZAM BIN AZMI

Date : 30 April 2009

iv

“I hereby declare that I have read this report and in my opinion this report is

sufficient in terms of the scope and quality for the award of Bachelor of Electronic

Engineering (Telecommunication Electronic) With Honours”

Signature : ………………………………………

Supervisor’s Name : IR. CHAIRULSYAH WASLI

Date :

v

DEDICATION

Special dedication to my beloved father and mother, my entire sibling and my kind

hearted supervisor Ir. Chairulsyah Wasli and my dearest friends.

vi

ACKNOWLEDGEMENT

Firstly, I would like to thank Allah because with His blessing I am able to

prepare this report and final project for Universiti Teknikal Malaysia Melaka. I wish

to thank all those who helped and encouraged me to complete my Bachelor of

Electronic Engineering (Telecommunication Electronics).

I would like to extend my sincere gratitude to my supervisor, Ir. Chairulsyah

Wasli, for his assistance and guidance toward the progress of this thesis project.

Through the year, Ir. Chairulsyah Wasli has been patiently monitoring my progress

and guided me in the right direction and offering encouragement. Obviously the

progress I had now will be uncertain without his assistance.

Likewise, I would like to thank my second supervisor, Dr Abdul Samad Bin

Shibghatullah for his assistance in creating animation by using the suitable software

and make this project possible. I would like to thank Hafizul for his encouragement

and help. Special thank to my friends Hafiz Nazar, Al-Amin and all my housemate

for giving me support and encourage me to finish this report.

This project would not have been like this if they not given great support and

encouragement on me when other academic assignments and test has pressured me.

The golden glory for me was during accomplishing this project is when my project

successfully completed in the right path.

Most of all, I would like to thank my parents for their unending support, and

my brother, whose mere existence keeps me motivated.

vii

ABSTRACT

The purpose of this project was to measure the fiber optic faults by using

Optical Time Domain Reflectrometer (OTDR) and at the same time to analyze fiber

optic faults. The software which will be used is based on the existing OTDR

simulation. The cases of fiber optic faults were learned before upgrade the OTDR

simulation. Each case is represented in form of graph for normal condition and

abnormal condition. Flash CS3 software was used to create each graph in animation

form. Then, the OTDR instrument was learned in detail by applying the instrument in

field study. The true result of fiber optic faults was investigated by using the

instrument. The result from theoretical and experimental OTDR will be compared to

ensure the valid results are obtained. The experimental OTDR is set for students in

Opto electronic laboratory. From this experiment, students can easy to understand the

operation of OTDR and they can investigate a few of events in fiber optic cable

efficiently.

viii

ABSTRAK

Tujuan projek ini ialah untuk mengukur tingkat kerosakan fiber optik dengan

menggunakan Optical Time Domain Reflectrometer (OTDR) dan pada masa yang

sama untuk menganalisa kerosakannya. Software yang akan digunakan adalah

berdasar pada simulasi OTDR yang sedia ada. Kes-kes kerosakan fiber optik

dipelajari sebelum menambah baik simulasi OTDR. Setiap kes diwakili dalam

bentuk graf untuk keadaan normal dan sebaliknya. Software Flash CS3 digunakan

untuk membuat graf dalam bentuk animasi. Kemudian, alat OTDR dipelajari dengan

mendalam, dengan menggunakan alat tersebut pada kajian lapangan. Keputusan

sebenar kerosakan fiber optik dikaji dengan menggunakan alat tersebut. Keputusan

daripada teori dan eksperimen akan dibandingkan untuk memastikan keputusan yang

betul diperolehi. Eksperimen OTDR dibuat untuk memudahkan pelajar menjalani

eksperimen ini pada masa akan datang. Para pelajar akan dapat memahami

bagaimana OTDR ini berfungsi daripada awal hingga akhir selepas mereka

melakukan eksperimen ini.

ix

TABLE OF CONTENTS

CHAPTER TITLE PAGE

THESIS TITLE i

DECLARATION iii

DEDICATION v

ACKNOWLEDGEMENT vi

ABSTRACT vii

ABSTRAK viii

TABLE OF CONTENTS ix

LIST OF TABLES xii

LIST OF FIGURES xiii

LIST OF SYMBOLS xv

I INTRODUCTION 1

1.1 PROJECT BACKGROUND 1

1.2 SCOPE OF WORKS 2

1.3 PROBLEMS STATEMENT 2

1.4 PROJECT OBJECTIVES 3

1.5 PROJECT’S METHODOLOGY 3

1.6 REPORT STRUCTURE 5

x

II LITERATURE REVIEW 6

2.1 INTRODUCTION 6

2.2 FIBER OPTIC LINK 7

2.3 OPTICAL FIBER CABLE 8

2.4 FIBER CLASSIFICATIONS 10

2.4.1 Single-Mode Step-Index 10

2.4.2 Multimode Step-Index 11

2.4.3 Multimode Graded-Index 12

2.5 PRINCIPLE OF OPERATION 12

2.6 ATTENUATION IN FIBER OPTIC 13

2.6.1 Dispersion 14

2.6.1.1 Modal Dispersion 15

2.6.1.2 Chromatic Dispersion 15

2.6.1.3 Polarization Dispersion 16

2.6.2 Absorption 17

2.6.3 Scattering 18

2.6.3.1 Stimulated Raman Scattering 19

2.6.3.2 Stimulated Brillouin Scattering 19

2.6.4 Optical Return Loss 19

2.7 APPLICATION OF OTDR 20

III METHODOLOGY 21

3.1 INTRODUCTION 21

3.2 COLLECTION DATA 21

3.3 PROJECT PLANNING 22

3.4 ANIMATION TROUBLESHOOTING 23

3.5 INTRODUCTION OF OTDR 23

3.6 THE WORK OF OTDR 25

3.7 INFORMATION IN THE OTDR TRACE 28

3.7.1 Overload Recovery 29

3.7.2 Ghosts 30

xi

3.8 OVERCOMING BACKSCATTER ERRORS 33

3.8.1 Resolution Limitations 33

3.8.2 Consideration For Multimode Fiber 34

IV RESULT AND DISCUSSION 36

4.1 RESULT FROM ANIMATION OF OTDR 36

4.2 CALCULATION RESULT AND ANALYSIS 42

4.2.1 Creating Formula 42

4.2.2 Backscattering 45

4.2.3 Reflectance 47

4.2.4 Reflection Amplitude-ORL

Specification 49

V CONCLUSIONS 55

5.1 CONCLUSION 55

5.2 RECOMMENDATION 56

REFERENCES 57

APPENDIXS

xii

LIST OF TABLE

TABLE TITLE PAGE

3.1 The function of each block OTDR 25

4.2 Output Power Values 44

4.3 Backscattering value 46

4.4 Typical values of backscatter coefficient for 48

Multimode fibers

xiii

LIST OF FIGURE

FIGURE TITLE PAGE

1.1 Project Flowchart . 4

2.1 Model of simple fiber optic data link 7

2.2 Fiber optic cable structure 8

2.3 Process of transmission light 9

2.4 Single-mode step index fiber 10

2.5 Multimode step-index optical fiber 11

2.6 Multimode Grade-index optical fiber 11

2.7 Snell’s law 12

2.8 Typical Dispersion vs. Wavelength Curves 14

2.9 Lingering materials 16

3.1 Gantt chart 19

3.3 The block diagram of the conventional OTDR 21

3.4 Scattering in an optical fiber 23

3.5 OTDR Display 24

3.6 Increasing the pulse width increases the backscatter level 24

3.7 OTDR trace information 26

3.8 OTDR launch pulse and launch cable 28

3.9 OTDR ghosts 29

3.10 Loss errors in OTDR measurements 30

xiv

LIST OF FIGURE

FIGURE TITLE PAGE

3.11 The OTDR pulse length limits its resolution . 34

3.12 OTDR see middle of multimode fiber core 35

4.1 Build of OTDR buttons 36

4.2 Display of graph case 1 37



4.5 Comparing of each graph in a figure 39

4.6 Display of graph from oscilloscope 40


4.8 The fiber optic block diagram 42

4.9 The loss of fiber optic 43

4.10 Graph of output power versus length 45

4.11 Graph of backscattering versus distance 47

4.12 ORL value of a reflection feature 49

4.13 OTDR pulse generator software 52

4.14 Building of an experimental OTDR 52

4.15 Measurement of power 53

4.16 Result of Experimental OTDR 53

xv

LIST OF SYMBOL / ACRONYM

ADC Analog Digital Converter

APD Avalance Photodiode

DC Direct Current

GI Graded Index

LED Light Emitting Diode

OTDR Optical time domain reflectrometer

PD Photo diode

SI Step Index

I/O Input and Output

Pi Input power

Pin Incident power

PT Transferring power

Pref Reflected power

Po Output power

a Attenuation

R Reflectance

l Length

L Loss

d distance

K @ B (s-1) Backscattering coefficient

A Reflection amplitude (in dB), as measured by the OTDR

�T OTDR measurement pulse width (in nanoseconds)

V Voltage

xvi

APPENDIX LIST

APPENDIX TITLE PAGES

A YOKOGAWA OTDR 58

B Fiber optic patch cord 68

C Characteristics of fiber 70

D Experimental OTDR Laboratory 72-84

CHAPTER I

INTRODUCTION

1.1 PROJECT BACKGROUND

In telecommunication field, fiber optic cable is the main part of transmission

of data. So, one of the main maintenance instruments fiber optic cable is optical

time-domain reflectrometer (OTDR). This instrument is used to test fiber links by

detecting losses and to know what types of faults have occurred on these links, as

well as where they are located. Generally, there are a few types of fiber faults likes

overload recovery, ghosts and backscatter variability errors.

Before this instrument is used in fiber optic cable plant, we should understand

how it works, the function of its buttons and what the types of types of faults. If not,

we will face problems of using it. We should have sufficient knowledge of OTDR

operation to ensure that the good data can be obtained and it will be used optimally.

This project is targeted to accomplish finish in six months timeline. The

ultimate goal is to examine the OTDR in detail and show the examples of good and

bad data by using flash CS3 software. Beside this, experimental OTDR is set for

optoelectronic laboratory which will be used by students.

2

1.2 SCOPES OF WORK

The scopes of work for the project include the following areas:

i. The study and understanding of OTDR the cases of fiber optic faults.

ii. Build the animation for fiber faults cases by using Flash CS3.

iii. Find the a few types of OTDR simulation and investigate them.

iv. Find the true result of OTDR cases and compare with theoretical animation.

v. The analysis of the fiber optic faults from the OTDR instrument.

Other scopes of work include:

1. Maintain good log book record

2. Prepare the necessary documents

3. Publishing final report

4. Project Presentation

1.3 PROBLEM STATEMENTS

Today, fiber optic cable is used widely for communication system which is

used for transmitting the signal or data. Therefore, the maintenance of fiber optic

cable should be done frequently to ensure the best serves are obtained by subscribers.

There are many equipments are used for the maintenance of fiber optic cable such as

OTDR. Generally, OTDR is used to identify optical cable fault. There are some

reasons to analysis and measurement fiber optic faults by OTDR. One of the reasons

is OTDR set is very expensive. The problem statement in this project is to show the

simulation of an OTDR where it is will be used for knowing better OTDR. So, the

function of the OTDR will be utilized maximally.

3

1.4 PROJECT OBJECTIVES

Due to the problem statement stated above, it’s cleared that the objectives of

the project are:

i. To know the function of OTDR.

ii. To make the OTDR animation

iii. To analysis the OTDR from theoretical and measurement aspect.

iv. To find out the advantage and disadvantages of OTDR.

1.5 PROJECT’S METHODOLOGY

Phase1:-

Meet and discuss with my supervisors Ir. Chairulsyah Bin Abdul Wasli and

Dr Abdul Samad Bin Shibghatullah. Show the project progress to them. Get the more

information about OTDR from supervisor, internet, books, journal, thesis, and so on.

Firstly, try to understand the concept & desired result for this OTDR cases.

Phase2:-

For this phase, discuss with my second supervisor Dr Abdul Samad Bin

Shibghatullah and do surveys on animation software for find the best method. Find

the chosen software and learn it from supervisor, internet and books for showing the

best result of OTDR cases animation.

Phase3:-

For this phase, prove a few of fiber optic fault cases by representing them in

graphs and block diagram. Design the animation of OTDR cases by using FlashCS3

software. Show the design of animation to supervisors and make correction of the

design.

4

Phase4:-

For this phase, set the experimental OTDR for lab optoelectronic which will

be used by students. Finally, submit the thesis of this project. Figure 1.1 shows the

project flowchart.

Figure 1.1 Project Flowchart

5

1.6 REPORT STRUCTURE

This report is organized in five chapters. The first chapter gives the brief

introduction of analysis and measurement of fiber optic fault by OTDR. The

objectives and scope of the project is also explained in this chapter as follows:

Chapter I : Covers the introduction

Chapter II : Covers the literature review

Chapter III : Covers the design methodology

Chapter IV : Cover the result for the project and expected result

Chapter V : Conclusion and discussion

CHAPTER II

LITERATURE REVIEW

2.1 INTRODUCTION

This chapter will look into the various aspects and the methods on research

methodology on project. This chapter will show the concept of the actual fiber optic

cable and the various related analysis. Furthermore, this chapter will show the

necessary enhancement that will make this equipment, OTDR (Optical time Domain

Reflectrometer) much more efficient equipment. Literature Review is important in

each project as a base for gathering information necessary to complete the project.

All information is gathered from various sources such as:-

1. Journal

2. Books

3. Conference Transcript

4. Thesis

5. Patent

6. Website

After searching through all this various material, all information will be

filtered to be related to OTDR. All this information will be compiled to be included

in the report.

2.2

considered for the premises environment. The link of fiber optic data communication

should be learned to know how the data is transferre

of simple fiber optic data link is shown in Figure 2.1. The principle of an optical

communications system is to transmit a signal through an optical signal through an

optical fiber to a distant receiver. The electrical sign

domain at the transmitter and is converted back into the original electrical signal at

the receiver.[4]

2.2 FIBER OPTIC LINK

The simple fiber optic data link is the main part in fiber optic which should be







the receiver.[4]

There are three main parts in a model of simple fiber optic

as source-user pair, transmitter and receiver. Refer to Figure 2.1 above, the fiber

optic cable establishing the Transmission Medium with the connectors that provide

the interface of the Transmitter to the Transmission Medium and the Trans

Medium to the Receiver.

FIBER OPTIC LINK








the receiver.[4]

Figure 2.1 Model of "simple" fiber optic data link


user pair, transmitter and receiver. Refer to Figure 2.1 above, the fiber




Figure 2.2 Process of transmission light in fiber optic cable

FIBER OPTIC LINK






























should be learned to know how the data is transferred from source to user. The model



optical fiber to a distant receiver. The electrical signal is converted into the optical










d from source to user. The model



al is converted into the optical



There are three main parts in a model of simple fiber optic which are known












which are known



the interface of the Transmitter to the Transmission Medium and the Transmission


7








which are known



mission

8

Fiber optic cable functions as a "light guide," guiding the light introduced at

one end of the cable through to the other end. The light source can either be a light-

emitting diode (LED)) or a laser. The light source is pulsed on and off, and a light-

sensitive receiver on the other end of the cable converts the pulses back into the

digital ones and zeros of the original signals.

Even laser light shining through a fiber optic cable is subject to loss of

strength, primarily through dispersion and scattering of the light, within the cable

itself. When the faster laser is applied, the dispersion of light is greater. Light

strengtheners, called repeaters, may be necessary to refresh the signal in certain

applications.

2.3 OPTICAL FIBER CABLE

In an optical fiber cable, it contains one or more optical fibers. The optical

fiber elements are typically individually coated with plastic layers and it also

contained in a protective tube suitable for the environment where the cable will be

installed. The actual fiber portion of an optical is generally considered to include

both the fiber core and its cladding.

Figure 2.3 below illustrates the fiber optic cable structure. The core is the

transparent glass (or plastic) component of the cable. Light shines through it from

one end to the other. The cladding, which is a glass sheath that surrounds the core, is

a key component. Like a mirror, it reflects light back into the core. As light passes

through the cable, its rays bounce off the cladding in different ways.

The loose buffer consists of plastic tube, which is over twice the fiber

diameter in size and serves as a shield from stresses and temperature changes. As the

fiber experiences bending, pressure, or extreme temperatures, the buffer protects the

fiber and leaves room for movement and expansion. The tight buffer consists of a

plastic buffer deposited directly on the fiber coating. While differences in thermal

expansion between fiber and buffer may cause microbends, this configuration

analysis and measurement fiber optic fault by using optical time domain reflectrometer (otdr)

Documents

chairulsyah wasli date

akwanizam bin azmi date

award of bachelor

thesis project

tajuk projek

measurement fiber optic

honours signature

final project