Single longitudinal mode fiber laser with integration of gallium-erbium co-doped fiber

Single longitudinal mode (SLM) lasers have gained much attention because of its ability to generate narrow linewidth output with low phase noise necessary for applications in optical communication and sensing. The generation of SLM in fiber laser is highly desirable due to its excellent perfor...

Full description

Saved in:
Bibliographic Details
Main Author: Mohamed Halip, Nor Hafizah
Format: Thesis
Language:English
Published: 2016
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/66813/1/FK%202016%20171%20IR.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
id my-upm-ir.66813
record_format uketd_dc
spelling my-upm-ir.668132019-02-01T01:50:11Z Single longitudinal mode fiber laser with integration of gallium-erbium co-doped fiber 2016-12 Mohamed Halip, Nor Hafizah Single longitudinal mode (SLM) lasers have gained much attention because of its ability to generate narrow linewidth output with low phase noise necessary for applications in optical communication and sensing. The generation of SLM in fiber laser is highly desirable due to its excellent performance and coupling simplicity. The issue however, is the complexity imposed by the inherently long cavity length and doped fiber gain medium, which lead to small free spectral range (FSR) and broad gain bandwidth. The experimental work presented in this thesis demonstrates SLM operation using Ga- EDF as gain medium together with several mode filtration techniques in the laser setup. High Erbium ion concentration in the fiber leads to high gain coefficient allowing short gain medium length to be used hence reducing the cavity length and widening the FSR. Ring cavity configuration employing optimum Ga-EDF length of 2 m was employed as the base structure. In order to suppress and filter the multi longitudinal modes, tunable bandpass filter (TBF), sub-ring structure and cascaded dissimilar fiber taper were utilized in this laser system. Each of the filter mechanism was tested individually within the laser cavity to assess its performance. Once the performance of each filter was obtained, all of them were deployed into the laser system. Ultimately, the 1561.47 nm SLM output was able to achieve a narrow linewidth laser of 1.19 kHz with output power of 1.814 mW and optical signal-to-noise ratio of 55.37 dB. Additionally, the stability and tunability of the laser were investigated. The laser can be tuned from 1522 nm to 1563 nm by tuning the TBF and 0.16 dB of power fluctuation was observed in duration of one hour. Evidently, the use Ga-EDF is feasible and significant for SLM operation thanks to its high gain coefficient. Simple mode selectors such as TBF, sub-ring cavity and dissimilar cascaded tapered fiber are influential as longitudinal mode eliminator. The findings from this study highlighted the attractiveness of high dopant co-doped fiber as gain medium for various laser configuration. Among the works that had been proposed by researchers, to the best of our knowledge, this is the first SLM laser demonstration utilizing Ga-EDF as the gain medium. Composite materials Lasers Fiber optics 2016-12 Thesis http://psasir.upm.edu.my/id/eprint/66813/ http://psasir.upm.edu.my/id/eprint/66813/1/FK%202016%20171%20IR.pdf text en public masters Universiti Putra Malaysia Composite materials Lasers Fiber optics
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
topic Composite materials
Lasers
Fiber optics
spellingShingle Composite materials
Lasers
Fiber optics
Mohamed Halip, Nor Hafizah
Single longitudinal mode fiber laser with integration of gallium-erbium co-doped fiber
description Single longitudinal mode (SLM) lasers have gained much attention because of its ability to generate narrow linewidth output with low phase noise necessary for applications in optical communication and sensing. The generation of SLM in fiber laser is highly desirable due to its excellent performance and coupling simplicity. The issue however, is the complexity imposed by the inherently long cavity length and doped fiber gain medium, which lead to small free spectral range (FSR) and broad gain bandwidth. The experimental work presented in this thesis demonstrates SLM operation using Ga- EDF as gain medium together with several mode filtration techniques in the laser setup. High Erbium ion concentration in the fiber leads to high gain coefficient allowing short gain medium length to be used hence reducing the cavity length and widening the FSR. Ring cavity configuration employing optimum Ga-EDF length of 2 m was employed as the base structure. In order to suppress and filter the multi longitudinal modes, tunable bandpass filter (TBF), sub-ring structure and cascaded dissimilar fiber taper were utilized in this laser system. Each of the filter mechanism was tested individually within the laser cavity to assess its performance. Once the performance of each filter was obtained, all of them were deployed into the laser system. Ultimately, the 1561.47 nm SLM output was able to achieve a narrow linewidth laser of 1.19 kHz with output power of 1.814 mW and optical signal-to-noise ratio of 55.37 dB. Additionally, the stability and tunability of the laser were investigated. The laser can be tuned from 1522 nm to 1563 nm by tuning the TBF and 0.16 dB of power fluctuation was observed in duration of one hour. Evidently, the use Ga-EDF is feasible and significant for SLM operation thanks to its high gain coefficient. Simple mode selectors such as TBF, sub-ring cavity and dissimilar cascaded tapered fiber are influential as longitudinal mode eliminator. The findings from this study highlighted the attractiveness of high dopant co-doped fiber as gain medium for various laser configuration. Among the works that had been proposed by researchers, to the best of our knowledge, this is the first SLM laser demonstration utilizing Ga-EDF as the gain medium.
format Thesis
qualification_level Master's degree
author Mohamed Halip, Nor Hafizah
author_facet Mohamed Halip, Nor Hafizah
author_sort Mohamed Halip, Nor Hafizah
title Single longitudinal mode fiber laser with integration of gallium-erbium co-doped fiber
title_short Single longitudinal mode fiber laser with integration of gallium-erbium co-doped fiber
title_full Single longitudinal mode fiber laser with integration of gallium-erbium co-doped fiber
title_fullStr Single longitudinal mode fiber laser with integration of gallium-erbium co-doped fiber
title_full_unstemmed Single longitudinal mode fiber laser with integration of gallium-erbium co-doped fiber
title_sort single longitudinal mode fiber laser with integration of gallium-erbium co-doped fiber
granting_institution Universiti Putra Malaysia
publishDate 2016
url http://psasir.upm.edu.my/id/eprint/66813/1/FK%202016%20171%20IR.pdf
_version_ 1747812410493763584