The University of Southampton
University of Southampton Institutional Repository

Investigation of nonlinear processes and device designs applicable to the creation of a compact, broadly tunable laser based on a tantalum pentoxide planar lightwave circuit platform

Investigation of nonlinear processes and device designs applicable to the creation of a compact, broadly tunable laser based on a tantalum pentoxide planar lightwave circuit platform
Investigation of nonlinear processes and device designs applicable to the creation of a compact, broadly tunable laser based on a tantalum pentoxide planar lightwave circuit platform
Nonlinear photonic devices utilize phase-matched parametric wavelength conversion in a nonlinear medium to create a widely tunable pulsed laser source. Currently most of nonlinear lasers are based on bulk optics or photonic fibres. Lasers based on bulk optics utilizing nonlinear crystals in conjunction with high intensity pulsed laser pumps, which are very powerful and often used as pump lasers for nonlinear experiments, but they are very large in size, and expensive to purchase. Although marketed as ‘turn key’ solutions, they require expert alignment, are difficult to use and are not suitable for deployment to environments other than environmentally stable optics labs. The photonic crystal fibres based lasers are very useful for optical communication purposes, but they are not as powerful as the bulk optics lasers and hard to be integrated with semiconductor devices due to their cylindrical structures. This thesis investigates the viability of creating an alternative widely tunable laser in a planar lightwave circuit (PLC) format. The overall aim of this project was to investigate the viability of creating a functional on-chip tunable laser, develop some of the key components, the base technologies required to do this job.

Required sub-components include efficient: supercontinuum generation, harmonic generation, and parametric wavelength conversion devices, all of which should ideally be powered by a compact, low cost, solid state pump source. To complicate matters further, requirements for parametric conversion include precise phase-matching of up to four participating beams, each of which may have a different wavelength. Furthermore, to provide broadband tunability, phase-matching condition must be maintained as the wavelengths of all participating beams are tuned. Hence the parametric conversion must take place in a device supporting ‘variable phasematching’.

One of the key sub-components of a broadband tunable laser is a supercontinuum (SC) source. Supercontinuum (SC) generation is a nonlinear optical phenomenon that generates a spectrum across a wide range of frequencies. The SC component is itself very useful for many optical applications including: optical coherence tomography
(OCT), frequency metrology, pulse compression, wavelength division multiplexing (WDM) and hence, attracts great research interests. Up to now, about 99% of the SC devices are based on optical fibres or nonlinear crystals. This thesis starts an in depth investigation of the generation of SC in planar waveguides reviewing the key linear and nonlinear optical effects associated with SC generation, making comparisons to prior literature.

All devices studied in this thesis were based on rib and ridge waveguides consisting of a tantalum pentoxide ( 2 5 Ta O ) core and silicon dioxide ( 2 SiO ) cladding materials. The simulated dispersion properties of such planar waveguides are presented. The experimental results on frequency tripling, SC generation and parametric effects along the waveguides are demonstrated. Further optimization procedures and potential applications are suggested subject to the current results and the nonlinear properties obtained from the 2 5 Ta O waveguide samples.
Chen, Ruiqi
2198083c-19b4-40dd-a28e-5929b80577c5
Chen, Ruiqi
2198083c-19b4-40dd-a28e-5929b80577c5
Charlton, Martin
fcf86ab0-8f34-411a-b576-4f684e51e274
Lagoudakis, Pavlos
ea50c228-f006-4edf-8459-60015d961bbf

Chen, Ruiqi (2010) Investigation of nonlinear processes and device designs applicable to the creation of a compact, broadly tunable laser based on a tantalum pentoxide planar lightwave circuit platform. University of Southampton, School of Electronics and Computer Science, Doctoral Thesis, 162pp.

Record type: Thesis (Doctoral)

Abstract

Nonlinear photonic devices utilize phase-matched parametric wavelength conversion in a nonlinear medium to create a widely tunable pulsed laser source. Currently most of nonlinear lasers are based on bulk optics or photonic fibres. Lasers based on bulk optics utilizing nonlinear crystals in conjunction with high intensity pulsed laser pumps, which are very powerful and often used as pump lasers for nonlinear experiments, but they are very large in size, and expensive to purchase. Although marketed as ‘turn key’ solutions, they require expert alignment, are difficult to use and are not suitable for deployment to environments other than environmentally stable optics labs. The photonic crystal fibres based lasers are very useful for optical communication purposes, but they are not as powerful as the bulk optics lasers and hard to be integrated with semiconductor devices due to their cylindrical structures. This thesis investigates the viability of creating an alternative widely tunable laser in a planar lightwave circuit (PLC) format. The overall aim of this project was to investigate the viability of creating a functional on-chip tunable laser, develop some of the key components, the base technologies required to do this job.

Required sub-components include efficient: supercontinuum generation, harmonic generation, and parametric wavelength conversion devices, all of which should ideally be powered by a compact, low cost, solid state pump source. To complicate matters further, requirements for parametric conversion include precise phase-matching of up to four participating beams, each of which may have a different wavelength. Furthermore, to provide broadband tunability, phase-matching condition must be maintained as the wavelengths of all participating beams are tuned. Hence the parametric conversion must take place in a device supporting ‘variable phasematching’.

One of the key sub-components of a broadband tunable laser is a supercontinuum (SC) source. Supercontinuum (SC) generation is a nonlinear optical phenomenon that generates a spectrum across a wide range of frequencies. The SC component is itself very useful for many optical applications including: optical coherence tomography
(OCT), frequency metrology, pulse compression, wavelength division multiplexing (WDM) and hence, attracts great research interests. Up to now, about 99% of the SC devices are based on optical fibres or nonlinear crystals. This thesis starts an in depth investigation of the generation of SC in planar waveguides reviewing the key linear and nonlinear optical effects associated with SC generation, making comparisons to prior literature.

All devices studied in this thesis were based on rib and ridge waveguides consisting of a tantalum pentoxide ( 2 5 Ta O ) core and silicon dioxide ( 2 SiO ) cladding materials. The simulated dispersion properties of such planar waveguides are presented. The experimental results on frequency tripling, SC generation and parametric effects along the waveguides are demonstrated. Further optimization procedures and potential applications are suggested subject to the current results and the nonlinear properties obtained from the 2 5 Ta O waveguide samples.

PDF
chenthesis.pdf - Other
Download (6MB)

More information

Published date: December 2010
Organisations: University of Southampton

Identifiers

Local EPrints ID: 171819
URI: https://eprints.soton.ac.uk/id/eprint/171819
PURE UUID: fe788bb8-505b-4060-8e3d-6b7fe05282e9

Catalogue record

Date deposited: 21 Jan 2011 16:31
Last modified: 18 Jul 2017 12:15

Export record

Contributors

Author: Ruiqi Chen
Thesis advisor: Martin Charlton
Thesis advisor: Pavlos Lagoudakis

University divisions

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.

×