The University of Southampton
University of Southampton Institutional Repository

A spectroscopic investigation of gallium lanthanum sulphide based glasses for optical devices

A spectroscopic investigation of gallium lanthanum sulphide based glasses for optical devices
A spectroscopic investigation of gallium lanthanum sulphide based glasses for optical devices
The optical communications network requires an efficient and cost effective 1.3 µm optical fibre-amplifier. The Praseodymium ion (Pr3+) 1.3 µm transition is the best candidate but requires a glass host with low phonon energy to produce a high radiative efficiency. Gallium Lanthanum Sulphide (GLS) based glasses are investigated as potential low phonon energy hosts. The work reported aims to link the spectroscopic results to the observed physical and optical properties and to the composition and atomic structure of the glasses. The Pr3+ doped GLS glass shows a high radiative quantum efficiency (RQE) for the 1.3µm transition and the lifetime of the transition is also long indicating a potentially useful glass dopant system. The Pr3+ enters the glass with a large coordination number and is sulphur coordinated. The Pr3+ doped GLS glass spectroscopic, optical and physical properties are found to be extremely susceptible to oxide impurities and added La203. In the Gallium Lanthanum Oxy-Sulphide (GLSO) glass the Pr3+ spectroscopy becomes excitation wavelength dependent. The temperature range of glass formation is increased as more oxide is added whilst the RQE and lifetime of the 1.3 µm transition are strongly reduced. This is explained through new oxide coordination for the Pr3+, which experiences a higher energy phonon and a different nephelauxetic shift of the Stark levels. The increased temperature range for glass formation of the GLSO glass is beneficial since the range of GLS glass is small. By adding metal halides to the GLS glass it was hoped that the improved glass forming properties of the GLSO glass could be kept along with the high RQE and lifetime of the 1.3 µm transition. The metal halide CSCI provided the largest increase in glass forming temperature range. The RQE was slightly reduced from the GLS value but much larger than the GLSO value. The lifetime was the longest measured. The dependence of the physical and optical properties on amount of metal halide was explained by changes in the bonding of the glass formers whilst the spectroscopic properties were most strongly influenced by bulk glass effects indicating a similar coordination for the Pr3+ in the GLS and CSCI GLS glasses. The doped GLS glass was not found to obey the simple multiphonon non-radiative decay formula with each rare-earth transition needing to be assessed individually.
Hector, Jason Roderick
e5570b2a-d996-4a14-85da-171090559b11
Hector, Jason Roderick
e5570b2a-d996-4a14-85da-171090559b11
Hewak, Daniel
87c80070-c101-4f7a-914f-4cc3131e3db0

Hector, Jason Roderick (1998) A spectroscopic investigation of gallium lanthanum sulphide based glasses for optical devices. University of Southampton, Optoelectronics Research Centre, Doctoral Thesis, 201pp.

Record type: Thesis (Doctoral)

Abstract

The optical communications network requires an efficient and cost effective 1.3 µm optical fibre-amplifier. The Praseodymium ion (Pr3+) 1.3 µm transition is the best candidate but requires a glass host with low phonon energy to produce a high radiative efficiency. Gallium Lanthanum Sulphide (GLS) based glasses are investigated as potential low phonon energy hosts. The work reported aims to link the spectroscopic results to the observed physical and optical properties and to the composition and atomic structure of the glasses. The Pr3+ doped GLS glass shows a high radiative quantum efficiency (RQE) for the 1.3µm transition and the lifetime of the transition is also long indicating a potentially useful glass dopant system. The Pr3+ enters the glass with a large coordination number and is sulphur coordinated. The Pr3+ doped GLS glass spectroscopic, optical and physical properties are found to be extremely susceptible to oxide impurities and added La203. In the Gallium Lanthanum Oxy-Sulphide (GLSO) glass the Pr3+ spectroscopy becomes excitation wavelength dependent. The temperature range of glass formation is increased as more oxide is added whilst the RQE and lifetime of the 1.3 µm transition are strongly reduced. This is explained through new oxide coordination for the Pr3+, which experiences a higher energy phonon and a different nephelauxetic shift of the Stark levels. The increased temperature range for glass formation of the GLSO glass is beneficial since the range of GLS glass is small. By adding metal halides to the GLS glass it was hoped that the improved glass forming properties of the GLSO glass could be kept along with the high RQE and lifetime of the 1.3 µm transition. The metal halide CSCI provided the largest increase in glass forming temperature range. The RQE was slightly reduced from the GLS value but much larger than the GLSO value. The lifetime was the longest measured. The dependence of the physical and optical properties on amount of metal halide was explained by changes in the bonding of the glass formers whilst the spectroscopic properties were most strongly influenced by bulk glass effects indicating a similar coordination for the Pr3+ in the GLS and CSCI GLS glasses. The doped GLS glass was not found to obey the simple multiphonon non-radiative decay formula with each rare-earth transition needing to be assessed individually.

PDF
Hector_1998_thesis_1300T.pdf - Other
Restricted to Repository staff only

More information

Published date: September 1998
Organisations: University of Southampton, Optoelectronics Research Centre

Identifiers

Local EPrints ID: 394392
URI: https://eprints.soton.ac.uk/id/eprint/394392
PURE UUID: cf68a3f4-c216-4dd4-bcaf-6f4ced522e9a
ORCID for Daniel Hewak: ORCID iD orcid.org/0000-0002-2093-5773

Catalogue record

Date deposited: 17 Jun 2016 15:50
Last modified: 06 Jun 2018 13:08

Export record

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 https://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.

×