Q-switching and mode-locking pulse generation based on passive techniques / Amri Ab. Rahman

The field of fiber lasers and fiber optic devices has experienced a sustained rapid growth despite witnessing the infamous 'telecom bubble burst'. All-fiber optic devices have inherent advantages of relatively low cost, compact design, light weight, low maintenance, and increased vibration...

Full description

Saved in:

Bibliographic Details
Main Author:	Ab. Rahman, Amri
Format:	Thesis
Language:	English
Published:	2015
Subjects:	Applied fiber optics Coatings Composite materials.
Online Access:	https://ir.uitm.edu.my/id/eprint/16060/1/TP_AMRI%20AB.%20RAHMAN%20CS%2015_5.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-uitm-ir.16060
record_format	uketd_dc
spelling	my-uitm-ir.160602022-03-10T02:56:43Z Q-switching and mode-locking pulse generation based on passive techniques / Amri Ab. Rahman 2015 Ab. Rahman, Amri Applied fiber optics Coatings Composite materials. The field of fiber lasers and fiber optic devices has experienced a sustained rapid growth despite witnessing the infamous 'telecom bubble burst'. All-fiber optic devices have inherent advantages of relatively low cost, compact design, light weight, low maintenance, and increased vibration tolerances. In this research, various new fiber lasers operating in Q-switching and mode-locking modes are proposed and demonstrated. At first, Q-switched Erbium-doped fiber lasers are demonstrated using a homemade passive saturable absorber (SA) based on singlewalled carbon nanotubes (SWCNTs) and graphene oxide films. For instance, with the use of a SWCNTs-Polyvinyl alcohol (PVA) SA, the laser has a multi-wavelength output at 1533.5 nm region with a repetition rate of 13.1 kHz, pulse width of 7.2 IlS and pulse energy of 21 nJ at the pump power of 64 mW. Two mode-locked EDFLs are also demonstrated using a homemade SA based on SWCNTs. For instance, a stable mode-locked EDFL is demonstrated using SWCNTs-PVA SA to generate a dissipative soliton pulse train operating in 1533.6 nm region. At pump power above the threshold value of 35.2 mW, the EDFL generates a self-starting pulse train with duration of 1.8 ps and repetition rate of 15.3 MHz. Besides showing good Qswitching and mode-locking performances, the proposed new saturable absorbers are easy to fabricate and cheap. Finally, we explore a new technique based on nonlinear polarization rotation (NPR) to demonstrate both Q-switched and modelocked fiber lasers.For instance, a stable passive Q-switched EDFL operating at 1534.5 nm region is demonstrated by employing a polarization dependent isolator and a highly nonlinear Erbium-doped fiber (EDF) to induce intensity dependent loss in a sufficiently-high lossy ring cavity. A simple NPR based EDFL with three switchable operation states have also been successfully demonstrated by employing a 6.9 km long dispersion shifted fiber (DSF) in the ring cavity. It firstly generates a square dissipative soliton pulse with a repetition rate of 87 kHz.Then, the laser produces a fundamental repetition rate of 29 kHz with a fixed pulse width of 8.5 JlS with the maximum pulse energy of 131.5 nJ is achieved at the pump power of 116.7 mW. Finally, the EDFL produces a fixed pulse width of 2.8 IJ,S and harmonic pulse repetition rate of 58 kHz. Q-switched and mode-locked EDFLs have wide and important applications in many fields such as optical communications, laser micromachining, optical sensors and laser ablation. 2015 Thesis https://ir.uitm.edu.my/id/eprint/16060/ https://ir.uitm.edu.my/id/eprint/16060/1/TP_AMRI%20AB.%20RAHMAN%20CS%2015_5.pdf text en public phd doctoral Universiti Teknologi MARA Faculty of Computer Science and Mathematics
institution	Universiti Teknologi MARA
collection	UiTM Institutional Repository
language	English
topic	Applied fiber optics Coatings Composite materials.
spellingShingle	Applied fiber optics Coatings Composite materials. Ab. Rahman, Amri Q-switching and mode-locking pulse generation based on passive techniques / Amri Ab. Rahman
description	The field of fiber lasers and fiber optic devices has experienced a sustained rapid growth despite witnessing the infamous 'telecom bubble burst'. All-fiber optic devices have inherent advantages of relatively low cost, compact design, light weight, low maintenance, and increased vibration tolerances. In this research, various new fiber lasers operating in Q-switching and mode-locking modes are proposed and demonstrated. At first, Q-switched Erbium-doped fiber lasers are demonstrated using a homemade passive saturable absorber (SA) based on singlewalled carbon nanotubes (SWCNTs) and graphene oxide films. For instance, with the use of a SWCNTs-Polyvinyl alcohol (PVA) SA, the laser has a multi-wavelength output at 1533.5 nm region with a repetition rate of 13.1 kHz, pulse width of 7.2 IlS and pulse energy of 21 nJ at the pump power of 64 mW. Two mode-locked EDFLs are also demonstrated using a homemade SA based on SWCNTs. For instance, a stable mode-locked EDFL is demonstrated using SWCNTs-PVA SA to generate a dissipative soliton pulse train operating in 1533.6 nm region. At pump power above the threshold value of 35.2 mW, the EDFL generates a self-starting pulse train with duration of 1.8 ps and repetition rate of 15.3 MHz. Besides showing good Qswitching and mode-locking performances, the proposed new saturable absorbers are easy to fabricate and cheap. Finally, we explore a new technique based on nonlinear polarization rotation (NPR) to demonstrate both Q-switched and modelocked fiber lasers.For instance, a stable passive Q-switched EDFL operating at 1534.5 nm region is demonstrated by employing a polarization dependent isolator and a highly nonlinear Erbium-doped fiber (EDF) to induce intensity dependent loss in a sufficiently-high lossy ring cavity. A simple NPR based EDFL with three switchable operation states have also been successfully demonstrated by employing a 6.9 km long dispersion shifted fiber (DSF) in the ring cavity. It firstly generates a square dissipative soliton pulse with a repetition rate of 87 kHz.Then, the laser produces a fundamental repetition rate of 29 kHz with a fixed pulse width of 8.5 JlS with the maximum pulse energy of 131.5 nJ is achieved at the pump power of 116.7 mW. Finally, the EDFL produces a fixed pulse width of 2.8 IJ,S and harmonic pulse repetition rate of 58 kHz. Q-switched and mode-locked EDFLs have wide and important applications in many fields such as optical communications, laser micromachining, optical sensors and laser ablation.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Ab. Rahman, Amri
author_facet	Ab. Rahman, Amri
author_sort	Ab. Rahman, Amri
title	Q-switching and mode-locking pulse generation based on passive techniques / Amri Ab. Rahman
title_short	Q-switching and mode-locking pulse generation based on passive techniques / Amri Ab. Rahman
title_full	Q-switching and mode-locking pulse generation based on passive techniques / Amri Ab. Rahman
title_fullStr	Q-switching and mode-locking pulse generation based on passive techniques / Amri Ab. Rahman
title_full_unstemmed	Q-switching and mode-locking pulse generation based on passive techniques / Amri Ab. Rahman
title_sort	q-switching and mode-locking pulse generation based on passive techniques / amri ab. rahman
granting_institution	Universiti Teknologi MARA
granting_department	Faculty of Computer Science and Mathematics
publishDate	2015
url	https://ir.uitm.edu.my/id/eprint/16060/1/TP_AMRI%20AB.%20RAHMAN%20CS%2015_5.pdf
_version_	1783733478098993152

Q-switching and mode-locking pulse generation based on passive techniques / Amri Ab. Rahman

Similar Items