The University of Southampton
University of Southampton Institutional Repository

Thulium doped fiber based lasers and amplifiers

Thulium doped fiber based lasers and amplifiers
Thulium doped fiber based lasers and amplifiers
In general, the work in this thesis could be divided into two parts, but more work is focused on the first part. Compared with aluminosilicate based Thulium-doped fibers (TDF), germanosilicate based TDFs have a blue-shifted absorption and emission cross-section in the transition from level 3F4 to level 3H6. Due to the quasi-three-level nature and broad fluorescence emission from level 3F4 to level 3H6, the germanosilicate based TDFs is envisaged to provide much higher gain at short wavelength below 1700nm. Combination of aluminosilicate based TDF and germanosilicate based TDF will provide a broadened emission window in the transition from level 3F4 to level 3H6. Literately, aluminosilicate based Thulium-doped fiber amplifiers (TDFAs) have been demonstrated from 1660nm to 2050nm. This broadband TDFAs combined with hollow-core photonic bandgap fiber provide a solution to the next generation fiber communication. Considering the long wavelength edge of extended L-band EDFA at 1620nm, there is an obvious gap between L-band EDFA and state of-the-art TDFAs. In order to seamlessly fill the gap, the short wavelength gain of a new germanosilicate based TDF (Tm/Ge co-doped fiber) is exploited by low-loss cavity management, long wavelength amplified spontaneous emission (ASE) suppression, thus realizing continuous wavelength lasing at short wavelength. Particularly wavelength tuning in the 1620-1660nm is realized by a compressively tunable fiber Bragg grating. When a band-pass filter is employed, ultrafast fiber lasers at 1650nm waveband is realized, which potentially unleash the application of thulium-doped fiber laser in the wavelength region below 1700nm. Intriguingly, for the germanate glass (multi-component glass mainly GeO2, but without SiO2), it provides a distinct environment for Tm3+ ions, in particular, the germanate glass host provide a much higher Tm-doping concentration capacity and longer fluorescence lifetime compared with silica glass. In the second part of the thesis, all the work are based on Tm-doped germanate glass fiber, which includes three main topics. The first topic focuses on the characterization of an in-house fabricated large mode area (LMA) Tm3+ -doped germanate glass fiber (TGF). Secondly, based on the in-band core-pumping scheme, a single mode fiber laser at 1950nm incorporating short length TGF is demonstrated with very high slope efficiency. Finally, with the short length of double-clad TGF, a compact TDFA with attractive gain is built operating in the 1880-2000nm waveband. Moreover, the double-clad TGF is incorporated as power amplifier in a master oscillator power amplifier (MOPA) system seeded by dissipative solitons, showing promise as a candidate for high-power pulse fiber laser with mitigated nonlinearity
University of Southampton
Chen, Shaoxiang
c7795b39-9ec3-4156-b3d7-73822fd31809
Chen, Shaoxiang
c7795b39-9ec3-4156-b3d7-73822fd31809
Richardson, David
ebfe1ff9-d0c2-4e52-b7ae-c1b13bccdef3

Chen, Shaoxiang (2019) Thulium doped fiber based lasers and amplifiers. University of Southampton, Doctoral Thesis, 125pp.

Record type: Thesis (Doctoral)

Abstract

In general, the work in this thesis could be divided into two parts, but more work is focused on the first part. Compared with aluminosilicate based Thulium-doped fibers (TDF), germanosilicate based TDFs have a blue-shifted absorption and emission cross-section in the transition from level 3F4 to level 3H6. Due to the quasi-three-level nature and broad fluorescence emission from level 3F4 to level 3H6, the germanosilicate based TDFs is envisaged to provide much higher gain at short wavelength below 1700nm. Combination of aluminosilicate based TDF and germanosilicate based TDF will provide a broadened emission window in the transition from level 3F4 to level 3H6. Literately, aluminosilicate based Thulium-doped fiber amplifiers (TDFAs) have been demonstrated from 1660nm to 2050nm. This broadband TDFAs combined with hollow-core photonic bandgap fiber provide a solution to the next generation fiber communication. Considering the long wavelength edge of extended L-band EDFA at 1620nm, there is an obvious gap between L-band EDFA and state of-the-art TDFAs. In order to seamlessly fill the gap, the short wavelength gain of a new germanosilicate based TDF (Tm/Ge co-doped fiber) is exploited by low-loss cavity management, long wavelength amplified spontaneous emission (ASE) suppression, thus realizing continuous wavelength lasing at short wavelength. Particularly wavelength tuning in the 1620-1660nm is realized by a compressively tunable fiber Bragg grating. When a band-pass filter is employed, ultrafast fiber lasers at 1650nm waveband is realized, which potentially unleash the application of thulium-doped fiber laser in the wavelength region below 1700nm. Intriguingly, for the germanate glass (multi-component glass mainly GeO2, but without SiO2), it provides a distinct environment for Tm3+ ions, in particular, the germanate glass host provide a much higher Tm-doping concentration capacity and longer fluorescence lifetime compared with silica glass. In the second part of the thesis, all the work are based on Tm-doped germanate glass fiber, which includes three main topics. The first topic focuses on the characterization of an in-house fabricated large mode area (LMA) Tm3+ -doped germanate glass fiber (TGF). Secondly, based on the in-band core-pumping scheme, a single mode fiber laser at 1950nm incorporating short length TGF is demonstrated with very high slope efficiency. Finally, with the short length of double-clad TGF, a compact TDFA with attractive gain is built operating in the 1880-2000nm waveband. Moreover, the double-clad TGF is incorporated as power amplifier in a master oscillator power amplifier (MOPA) system seeded by dissipative solitons, showing promise as a candidate for high-power pulse fiber laser with mitigated nonlinearity

Text
Final_thesis_unsigned - Version of Record
Available under License University of Southampton Thesis Licence.
Download (6MB)
Text
Permission to deposit thesis Shaoxiang Chen (003)
Restricted to Repository staff only

More information

Published date: 2019

Identifiers

Local EPrints ID: 455855
URI: http://eprints.soton.ac.uk/id/eprint/455855
PURE UUID: 55379569-9cce-49e8-a491-316746607718
ORCID for David Richardson: ORCID iD orcid.org/0000-0002-7751-1058

Catalogue record

Date deposited: 06 Apr 2022 17:04
Last modified: 17 Mar 2024 02:37

Export record

Contributors

Author: Shaoxiang Chen
Thesis advisor: David Richardson ORCID iD

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×