WIDEBAND OPTICAL AMPLIFIER USING HIGH...
Transcript of WIDEBAND OPTICAL AMPLIFIER USING HIGH...
WIDEBAND OPTICAL AMPLIFIER USING HIGH CONCENTRATION
ERBIUM DOPED FIBER IN SINGLE-PASS CONFIGURATION
SHAHIRAH SAADON
This Report Is Submitted In Partial Fulfillment Of Requirements For The
Bachelor Degree Of Electronic Engineering (Telecommunications Electronic)
Fakulti Kejuruteraan Elektronik Dan Kejuruteraan Komputer
Universiti Teknikal Malaysia Melaka
JUN 2013
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UNIVERSTI TEKNIKAL MALAYSIA MELAKA FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER
BORANG PENGESAHAN STATUS LAPORAN
PROJEK SARJANA MUDA II
Tajuk Projek :
Sesi Pengajian :
WIDEBAND OPTICAL AMPLIFIER USING HIGH CONCENTRATION ERBIUM DOPED FIBRE IN SINGLE PASS CONFIGURATION
Saya SHAHIRAH BINTI SAADON
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)
Tarikh: ……………………….. Tarikh: ………………………..
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“I hereby declare that this report is the result of my own work except for the
summary and quotes as cited in the reference”
Signature : …………………………………
Author : SHAHIRAH SAADON
Date : …………………………………
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“I hereby declare that I have read this report and in my opinion this report is
sufficient in terms of scope and quality for the award of the Bachelor of Electronics
Engineering (Telecommunications Engineering) With Honours”
Signature : …………………………………
Supervisor’s Name : ANAS BIN ABDUL LATIFF
Date : …………………………………
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ACKNOWLEDGEMENT
Firstly, I would like to be grateful to Allah s.w.t. as I am able to fulfil the
Bachelor Project successfully. I would like to take this opportunity to express my
appreciation to those who has helped me through during the completion of this
project, especially to my supervisor; Mr. Anas bin Abdul Latiff for guiding me and
lending his knowledge towards accomplishing this project. In addition, I am
indebted to the Technical Staff of the Faculty of Electronics Engineering and
Computer Engineering for aiding me in conducting the experiment for the project in
the laboratory.
I would also like to than my parents for giving their never ending moral
supports and my fellow colleagues for their helping hand and encouragement in
finishing this project.
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ABSTRACT
This report explores the wideband optical amplifier using high concentration
erbium doped fibre in single-pass configuration. The main objective is to study the
design of Erbium doped Fibre Amplifier (EDFA) with low pump power to satisfy the
requirements for green technology specification. The design parameter for the
optimised circuit needs to be determined to evaluate the performance of the amplifier
so that it is able to transmit data efficiently. All the parameters and the fundamental
theory are described in details. The simulation result obtained will be analysed and
discussed.
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ABSTRAK
Laporan ini menerokai penguat optik jalur lebar yang menggunakan “Erbium
Doped Fiber” berkepekatan tinggi dalam konfigurasi pas-tunggal. Objektif utama
adalah untuk menganalisis bentuk “Erbium Doped Fiber Amplifier” (EDFA) dengan
kuasa pam yang rendah bagi memenuhi keperluan spesifikasi technology hijau.
Parameter reka bentuk litar optimum perlu ditentukan untuk menilai prestasi penguat
ini supaya ia dapat mengantar data dengan berkesan. Semua pamameter dan teori
asas akan diterangkan secara terperinci. Keputusan simulasi yang diperolehi akan
dianalisis dan dibincangkan.
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CONTENTS
CHAPTER
I
TITLE
PROJECT TITLE
VERIFICATION STATUS FORM
DECLARATION FORM
SUPERVISOR CONFIRMATION FORM
ACKNOWLEDGEMENT
ABSTRACT
CONTENT
LIST OF TABLE
LIST OF FIGURE
ABBREVIATION
LIST OF APPENDIX
INTRODUCTION
1.1 Overview of the Project
1.2 Objectives
1.3 Problem Statement
1.4 Scope
1.5 Project Outcomes
1.6 Methodology
1.7 Thesis Structure
PAGE
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ii
iii
iv
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xi
xii
xiv
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1
3
3
4
5
5
6
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II
III
LITERATURE REVIEW
2.1 Introduction 7
2.2 Benefits of Fibre Optics 8
2.3 Basic Fibre Optic Communication System 9
2.4 Optical Amplifier 10
2.4.1 Semiconductor Optical Amplifier 13
2.4.2 Raman Amplifier 14
2.4.3 Erbium Doped Fiber Amplifier 16
2.4.3.1 Amplifier Gain 17
2.4.3.2 Amplifier Noise 19
2.4.3.3 Crosstalk 23
2.4.3.4 Output Power 23
2.4.3.5 Power Saturation 26
2.4.4 Comparison between SOA, Raman and 27
EDFA
2.4.5 Advantage and Disadvantage of EDFA, 28
Raman, SOA
2.5 Parameters of Optical Amplifier (Performance) 29
2.5.1 Gain 30
2.5.2 Noise 30
2.5.3 Signal-to-Noise Ratio 31
2.5.4 Bit Error Rate 31
2.5.5 Eye Pattern 31
2.6 Wideband Fiber Amplifier 32
2.7 OptiSystem Software 35
METHODOLOGY
3.1 Project Flow Chart 36
3.2 Software Flow Chart 39
3.3 Project Block Diagram 41
3.4 Experimental Procedure 42
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3.5 Parameters 43
IV RESULT AND DISCUSSION
4.1 Pump Laser Wavelength 45
4.1.1 980 nm Pump Laser 46
4.1.2 1480 nm Pump Laser 48
4.1.3 Optimized Pump Wavelength 50
4.2 Length of Fibre 54
4.3 Wideband Circuit 56
V CONCLUSION AND RECOMMENDATION
5.1 Conclusion 61
5.2 Recommendation 62
REFERENCES 64
APPENDIX 66
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LIST OF TABLES
TABLE
2.1
2.2
2.3
TITLE
Transmission Window
Characteristics of EDFA, Raman, and SOA
Advantages and Disadvantage of EDFA, Raman
and SOA
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27
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LIST OF FIGURES
FIGURE
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11(a)
2.11(b)
2.11(c)
2.11(d)
3.1
3.2
TITLE
Fiber Transmission Cable
Optical Amplifier Transmission Windows
Semiconductor Optical Amplifier Construction
Spontaneous Raman Scattering
Stimulated Raman Scattering
EDFA Configuration
Set-up for Measurement of Amplifier Gain in
EDFA
Energy Level Diagram
Evolution of Pump, Signal and ASE
Gain as a Function of Input and Output Signal
Powers
Serial Configuration
Parallel Configuration
S-, C-, L-Bands Hybrid Configuration
Hybrid Combination of Raman Amplifier and
EDFA
Final Year Project Flow Chart
Software Flow Chart
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25
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38
40
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3.3
3.4(a)
3.4(b)
3.5(a)
3.5(b)
4.1(a)
4.1(b)
4.2(a)
4.2(b)
4.3(a)
4.3(b)
4.3(c)
4.4(a)
4.4(b)
4.5(a)
4.5(b)
4.6(a)
4.6(b)
4.6(c)
Evaluation Performance 41
Wideband Series Configuration 42
Wideband Parallel Configuration 42
Single Pump Configuration 44
Bidirectional (Backward-Forward) Pump 44
Configuration
Graph of C-band at 980 nm 46
Graph of L-band at 980 nm 47
Graph of C-band at 1480 nm 48
Graph of L-band at 1480 nm 49
C-band Optimum Pump Laser Wavelength 51
L-band Optimum Pump Laser Wavelength 52
Wideband Optimum Pump Laser Wavelength 53
Graph of C-band at different length 54
Graph of L-band at different length 55
Series configuration of EDFA 56
Parallel configuration of EDFA 57
Graph of Wideband Serial Configuration 58
Graph of Wideband Parallel Configuration 59
Analysis of wideband optimized configuration 60
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ABBREVIATION
OA
EDFA
SOA
RA
NF
SNR
- Optical Amplifier
- Erbium Doped Fibre Amplifier
- Semiconductor Optical Amplifier
- Raman Amplifier
- Noise Figure
- Signal-to-Noise Ratio
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LIST OF APPENDIX
NO TITLE
A1 Table of C-band at Pump Wavelength of 980 nm
A2 Table of L-band at Pump Wavelength of 980 nm
B1 Table of C-band at Pump Wavelength of 1480 nm
B2 Table of L-Band at Pump Wavelength of 1480 nm
C1 Table of C-band at Different Length of Fibre
C2 Table of L-band at Different Length of Fibre
D1 Table of Wideband Serial Configuration
D2 Table of Wideband Parallel Configuration
PAGE
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CHAPTER 1
INTRODUCTION
Chapter one focuses on the project’s overview, project’s objective and problem
statement, scope of work, methodology and thesis structure. It will explain the
basics for the project which is wideband optical amplifier using high Erbium Doped
Fibre Amplifier in single-pass configuration. These will be explained in this chapter
to give guidance to what the project is about.
1.1 Overview of the Project
In order to transmit signals over long distances (more than 100 km) it
is compulsory to calculate and compensate the attenuation losses within the
fibre, during travelling and also due to few other factors. Originally, this was
performed using the optoelectronic module that consisted of the optical
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receiver, regeneration and equalisation system and also an optical transmitter
to transmit the data. Even though this arrangement was functional, it is
limited by the optical to electrical and electrical to optical conversions. Since
that, several types of optical amplifiers have been demonstrated to replace the
optical-electrical electronic regeneration system [1].
Erbium doped fibre amplifiers (EDFAs) is an optical repeater device
that is used to magnify the intensity of optical signals that are being carried
through a fibre optic telecommunication system. Commonly, an optical fibre
is doped with the rare earth element Erbium, which means that the Erbium is
added to the fibre core material as a dopant. This is so that the glass is able to
absorb light at one frequency and emits light at another frequency. Fibre
amplifiers are developed to support the Dense Wavelength Division
Multiplexing (DWDM) and to extend to the other wavelengths supported by
fibre optics. An external semiconductor laser couples light into the fibre at
infrared wavelengths of either 980 or 1480 nanometres. This operation will
excite the erbium atoms. Additional wavelengths between 1530 and 1620
nanometres infiltrate the fibre and stimulate the excited erbium atoms to emit
photons at the same wavelengths as the incoming signal. This operation
amplifies a flaccid signal to a greater power, affecting a magnification in the
signal strength.
This project simulated and evaluates the performance of the Erbium
Doped Fibre Amplifier in an optical transmission systems using the
OptiSystem Software. The performance of the amplifier is affected by few
parameters, which are; Optical Signal-to-Noise Ratio (OSNR), Bit Error Rate
(BER), and Noise Figure (NF). The problem faced on conducting this project
is to find the most excellent design parameter for the maximum utilization of
the Erbium Doped and with compact size using the Erbium Doped Fibre
Amplifier.
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1.2 Objectives
The objectives of this project are:
a. To study the design of wideband optical amplifier using high
concentration erbium-doped Fibre using the OptiSystem software.
b. To provide the design parameters for low power and compact for
optical amplifier using high concentration Erbium Doped Fibre.
c. To evaluate the performance of the high concentration Erbium Doped
Fibre amplifier based on the amplifiers gain and Noise Figure (NF)
and to analyse the simulation data obtained from the OptiSystem
software.
1.3 Problem Statement
Optical amplifiers have become an essential component in the long
haul fibre optic systems due to the demand for the longer length of
transmission. During the transmission of the signal through the fibre cable,
there bound to be some losses due to few factors that cannot be avoided. The
reasons why the optical amplifiers are required are:
• Typical fibre loss for 1.5 µm is 0.2 dB/km.
• After travelling for about 100km, the signals will be attenuated
by 20 dB.
• The optical signal needs to be amplified so that the Optical
Signal-to-Noise Ratio (OSNR) of the detected signal is not too
low and the Bit Error Rate (BER) does not becomes too high.
• The previous amplifier which is the Optical-Electrical-Optical
amplifier conversions is much more expensive as it requires
expensive high-speed electronics.
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• The most efficient and effective solution is to amplify the
signal optically by using the fibre amplifier because it is
lowest in cost, most efficient and most stable.
In order to increase the output power of the transmission system, the
amount of the optical amplifier will also need to be increased. However this
will also increase the costs. Therefore the best solution is by optimizing the
performance of the optical amplifier.
Currently, the most effectual solution in optimizing the performance
of the optical amplifier is by using the Erbium Doped Fibre Amplifier. This
is because their high gain and the ability to operate with low pump power.
Therefore, this project is to analyse the performance of the high concentration
Erbium Doped Fibre amplifier at different pumping value. The effectiveness
of the amplifier will be based on the value of the output that will be obtained.
The length of the fibre that is to be used in the amplifier will also need to be
reduced to reduce the cost needed for the construction of the amplifier. The
solution to this is by using the high concentration Erbium in the fibre to
enhance the energy excitement on the amplifier.
The design for the EDFA must fit the criteria of the objective, that it:
• It must be compact (try to minimize the length of fibre to be
used in the experiment.
• Try to use the lowest possible pump power to operate the
system, but with efficient result.
1.4 Scope
This project will focus primarily on the simulation of the wideband
optical amplifier using high concentration Erbium Doped Fibre in single pass
configuration. The simulation and tests will be done using the OptiSystem
Software. The performance of the optical amplifier will be evaluated based
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on the amplifier’s gain and Noise Figure (NF) obtained from the simulation
of a single mode fibre transmission link for wideband wavelength. The
fabrication or development of hardware of the high concentration of Erbium
Doped Fibre Optical Amplifier (EDFA) will not be covered in this project.
1.5 Project Outcomes
It is expected that by the end of this project, the parametric study for
the design of the high concentration EDFA in single-pass configuration that is
to be used for the wideband with desired parameter of high gain value and
low noise figure value can be obtained. In addition, the EDFA will be able to
simulate with low power and is compact size.
1.6 Methodology
This project starts off with acquiring the source and information
pertaining to the optical amplifier using high concentration Erbium Doped
Fibre. The sources and information are obtained from journals, reference
books, e-Books, magazines and also the internet. The information attained
will be based on the fundamental configuration of the optical amplifier in a
transmission link, advantages and disadvantages of EDFA, the parameters
related with EDFA. The circuit schematic diagram of the optical amplifier
using high concentration Erbium Doped Fibre is determined and then
simulated and tested using the OptiSystem software. The parameters
involved and varied are the number of pump (Single Pump or Bidirectional
Pump), the pump power (from 10 mW until 200 mW), the pump wavelength
(980 nm or 1480 nm), the fibre length (from 1 m until 2.5 m for C-band
application and from 7 m until 8.5 m for L-band application) and the input
signal power (0 dBm or -30 dBm). The amplifiers gain and Noise Figure
(NF) obtained from the simulation is analysed. The simulation process is
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repeated until the compatible design parameter for the wideband optical
amplifier is obtained.
1.7 Thesis Structure
Chapter 1 introduces the project and gives general idea regarding the
project. It includes the overview of the project, the objective, problem
statement, scope of project and project outcomes which will provide basic
idea and knowledge related with this project.
Chapter 2 illustrates and discusses the projects fundamental and
background. The concept and theory of the circuit diagram that will be used
in the project will be explained in details in this chapter.
Chapter 3 proposes the methodology of the project. The procedures
that will be used in conducting the project will be explained more thoroughly
in this chapter.
Chapter 4 presents the results that are obtained from the simulation of
the high concentration EDFA. The results obtained will also be discusses and
analysed in this chapter,
Chapter 5 will conclude all the information collected based on the
projects result. The results will be evaluated based on the findings and the
objectives of the project. Recommendations on how to enhance the project
will also be included in this chapter.
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CHAPTER 2
LITERATURE REVIEW
Chapter two focuses on the project’s background and other relevant information
related to the project such as the fundamentals of Erbium Doped Fibre Amplifier. It
will explain the basics for the project which is wideband optical amplifier using high
Erbium Doped Fibre Amplifier in single-pass configuration.
2.1 Introduction
Since its invention in the early 1970s, the use and the demand of
optical fibre have excessively grown. The applications of optical fibre today
are quite abundant [1]. With the eruption of the information traffic generated
with the use of internet, electronic commerce, computer network, multimedia,
voice, data and video, the requirement for a transmission medium with the
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bandwidth capabilities for handling such enormous amount of information is
essential. Fibre optics, with its comparatively infinite bandwidth has proven
to be the solution. When optical is the only transmission that can keep up
with and stay ahead of the accelerating demand for long haul requirements,
this means that the technology of the optical system is an essential part of the
human system [2]. Therefore, it is vital that we study the system in order to
develop the most intelligent fibre optic amplifier that fits the current needs to
allow for a more cost effective advance network infrastructure.
2.2 Benefits of Fibre Optics
The optical fibre system possesses several advantages over metallic-
based communication system [3]. These advantages include:
• Long distance signal transmission
The optical systems admits longer interval of signal transmission than
the metallic-based systems due to the low attenuation and superior
signal integrity.
• Large bandwidth, light weight, and small diameter
The present applications has the need to an ever increasing amount of
bandwidth. Therefore, it is important to acknowledge the space
constraints of many end users. The small diameter and light weight of
the optical cable makes the installation simple and practical, and helps
to save the conduit space.
• Non-conductivity
Due to its dielectric nature and no metallic components, the optical
fibres can be installed even in the areas with electromagnetic
interference (EMI) and radio frequency interference (RFI). It is also
ideal to be installed for the areas if high lightning strike incidence.
• Security
The dielectric nature of the optical fibre also makes it impossible to
remotely access the optical fibre. Accessing the fibre will require
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intervention that will be easily discovered by the security surveillance.
The conditions make the fibre favoured to governmental bodies,
banks and others with security concerns.
• Designed for future application needs
Fibre optics is affordable today, as the prices of the electronics fall
and the price of the optical cable remaining low. In the increasing
demands of the bandwidth as the technology advances, fibre will
continue to play an essential role in the long term accomplishment of
the telecommunications.
2.3 Basic Fibre Optic Communication System
The fibre optics is used as medium to carry information from one
point to another in the form of light. As the fibre optic is not electrical in
nature like the copper form of transmission, a basic fibre optic system is
made up of a transmitting device that converts an electrical signal into a light
signal, an optical fibre that carries the light and a receiver that accepts the
light signal and convert is back to electrical signal. The complexity of a fibre
optic system can range from a very simple system to a very prominent
system. A conventional optical communication system that is for the usage
of long distance, high bandwidth telecommunication that employs
wavelength-division multiplexing uses the Erbium doped fibre amplifier, an
external modulation that uses the DFB lasers with temperature compensation,
fibre Bragg gratings and high speed infrared photo-detectors [4].