The University of Southampton
University of Southampton Institutional Repository

Generation and manipulation of short optical pulses in fibre based systems

Generation and manipulation of short optical pulses in fibre based systems
Generation and manipulation of short optical pulses in fibre based systems
This thesis presents experimental and computational work on a variety of fibre based systems covering the generation, transmission, manipulation and amplification of short optical pulses (hundreds of femtoseconds to tens of picoseconds).
The construction and characterisation of an all-polarisation-maintaining fibre figure-8, passively mode-locked laser is presented. This was the first all-fibre passively mode-locked cavity constructed entirely of high birefringence, polarisation maintaining components. This enabled the generation of a single polarisation Eigen-state within the cavity, resulting in a source of high quality 2.3ps-6ps solitonic pulses with excellent environmental stability, despite the considerable length of the device (395m).
A computational model of a dispersion compensated standard fibre link using a fibre based four-wave mixing, midpoint spectral inversion (MPSI) technique was developed to provide qualitative and quantitative support to a 50km experimental system for the transmission of 6ps solitonic pulses. This model was then used to provide an estimate of the limitations to such systems presented by higher order dispersion, the results suggesting that links greater than 2500km at single channel bit-rates of 50GBit/s could be feasible.
The development of photorefractive fibre Bragg gratings has produced one of the most important and flexible fibre devices. Experimental and computational investigations of the interaction of short pulses with both uniform and linearly chirped gratings are presented, giving a useful insight into their dispersive effects and limitations for their use in more complex systems. The importance of apodisation for reducing the energy scattering from pulses after multiple reflections was clearly demonstrated through numerical modelling of such systems.
The application of long, linearly chirped fibre Bragg gratings to the compensation of chromatic dispersion in step-index fibres at potential bit-rates approaching 50GBit/s was demonstrated experimentally with the transmission of 16ps pulses over 100km. The use of two cascaded 4cm gratings exploited the linearity of these devices to further push the limits of compensation available.
One of the few limitations of fibre based short pulse sources is the relatively low pulse energies produced. This problem had been tackled through the use of chirped pulse amplification (CPA) to circumvent the limitations imposed by fibre nonlinearities to amplification in EDFAs, however the problems of energy extraction from the amplifier fibre remained. The development and application to CPA of a large mode-area EDFA designed to improve pulse energy extraction is presented. The generation of 32µJ pulses directly from the amplifier represented a significant increase in both energy and pulse quality over previously reported systems, demonstrating the potential of such amplifier designs for a range of high energy/intensity pulse applications.
Taverner, D.
b8f04b32-4ce1-4d7d-9fd2-298bff142b96
Taverner, D.
b8f04b32-4ce1-4d7d-9fd2-298bff142b96
Richardson, David
ebfe1ff9-d0c2-4e52-b7ae-c1b13bccdef3

Taverner, D. (1996) Generation and manipulation of short optical pulses in fibre based systems. University of Southampton, Optoelectronics Research Centre, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

This thesis presents experimental and computational work on a variety of fibre based systems covering the generation, transmission, manipulation and amplification of short optical pulses (hundreds of femtoseconds to tens of picoseconds).
The construction and characterisation of an all-polarisation-maintaining fibre figure-8, passively mode-locked laser is presented. This was the first all-fibre passively mode-locked cavity constructed entirely of high birefringence, polarisation maintaining components. This enabled the generation of a single polarisation Eigen-state within the cavity, resulting in a source of high quality 2.3ps-6ps solitonic pulses with excellent environmental stability, despite the considerable length of the device (395m).
A computational model of a dispersion compensated standard fibre link using a fibre based four-wave mixing, midpoint spectral inversion (MPSI) technique was developed to provide qualitative and quantitative support to a 50km experimental system for the transmission of 6ps solitonic pulses. This model was then used to provide an estimate of the limitations to such systems presented by higher order dispersion, the results suggesting that links greater than 2500km at single channel bit-rates of 50GBit/s could be feasible.
The development of photorefractive fibre Bragg gratings has produced one of the most important and flexible fibre devices. Experimental and computational investigations of the interaction of short pulses with both uniform and linearly chirped gratings are presented, giving a useful insight into their dispersive effects and limitations for their use in more complex systems. The importance of apodisation for reducing the energy scattering from pulses after multiple reflections was clearly demonstrated through numerical modelling of such systems.
The application of long, linearly chirped fibre Bragg gratings to the compensation of chromatic dispersion in step-index fibres at potential bit-rates approaching 50GBit/s was demonstrated experimentally with the transmission of 16ps pulses over 100km. The use of two cascaded 4cm gratings exploited the linearity of these devices to further push the limits of compensation available.
One of the few limitations of fibre based short pulse sources is the relatively low pulse energies produced. This problem had been tackled through the use of chirped pulse amplification (CPA) to circumvent the limitations imposed by fibre nonlinearities to amplification in EDFAs, however the problems of energy extraction from the amplifier fibre remained. The development and application to CPA of a large mode-area EDFA designed to improve pulse energy extraction is presented. The generation of 32µJ pulses directly from the amplifier represented a significant increase in both energy and pulse quality over previously reported systems, demonstrating the potential of such amplifier designs for a range of high energy/intensity pulse applications.

Full text not available from this repository.

More information

Published date: May 1996
Organisations: University of Southampton

Identifiers

Local EPrints ID: 398738
URI: https://eprints.soton.ac.uk/id/eprint/398738
PURE UUID: c08aadc1-5963-420f-89c8-b99bf51709c9

Catalogue record

Date deposited: 01 Aug 2016 15:31
Last modified: 17 Jul 2017 18:28

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.

×