The University of Southampton
University of Southampton Institutional Repository

Laser-induced ferroelectric and photonic structures in lithium niobate crystals

Laser-induced ferroelectric and photonic structures in lithium niobate crystals
Laser-induced ferroelectric and photonic structures in lithium niobate crystals
The influence of laser illumination on ferroelectric domain engineering, waveguide formation and surface micro-structuring in lithium niobate (LN) is investigated. The ability to combine and to manipulate the size and depth of poling inhibited (PI) domains, which are produced by UV-laser irradiation of the +z face of congruent lithium niobate crystals followed by electric field poling, is demonstrated. It is therefore possible to produce complex domain structures, by partially overlapping individual UV laser irradiated tracks thus increasing the utility of this method for the fabrication of surface microstructures. Investigation of the electro-optic performance of ferroelectric/photonic composite structures, which occur naturally as a consequence of the PI process, had shown a significant enhancement (by ~ 36.7 % under the experimental conditions used) of the inherent electro-optic coefficient of the crystal attributed to large range stress at the domain boundaries. The feasibility of UV laser induced PI domain engineering in proton exchanged waveguides in LN was investigated showing that PI domain inversion is in principle possible. It requires however high laser intensity illumination which may produce significant surface damage. Additionally it was found that the proton concentration was also affected by the UV laser irradiation resulting in modifications of the original proton exchanged waveguide structure. Finally, an alternative to UV laser irradiation as a means for PI domain engineering and waveguide formation in LN is presented. This alternative method uses visible c.w. laser irradiation and an amorphous silicon absorbing layer to couple energy into the LN crystal thus emulating the direct absorption that occurs at UV wavelengths.
University of Southampton
Zisis, Grigorios
45a0bf08-5ab7-4d9b-9ad9-65ca7bf739a9
Zisis, Grigorios
45a0bf08-5ab7-4d9b-9ad9-65ca7bf739a9
Mailis, Sakellaris
233e0768-3f8d-430e-8fdf-92e6f4f6a0c4

Zisis, Grigorios (2016) Laser-induced ferroelectric and photonic structures in lithium niobate crystals. University of Southampton, Doctoral Thesis, 127pp.

Record type: Thesis (Doctoral)

Abstract

The influence of laser illumination on ferroelectric domain engineering, waveguide formation and surface micro-structuring in lithium niobate (LN) is investigated. The ability to combine and to manipulate the size and depth of poling inhibited (PI) domains, which are produced by UV-laser irradiation of the +z face of congruent lithium niobate crystals followed by electric field poling, is demonstrated. It is therefore possible to produce complex domain structures, by partially overlapping individual UV laser irradiated tracks thus increasing the utility of this method for the fabrication of surface microstructures. Investigation of the electro-optic performance of ferroelectric/photonic composite structures, which occur naturally as a consequence of the PI process, had shown a significant enhancement (by ~ 36.7 % under the experimental conditions used) of the inherent electro-optic coefficient of the crystal attributed to large range stress at the domain boundaries. The feasibility of UV laser induced PI domain engineering in proton exchanged waveguides in LN was investigated showing that PI domain inversion is in principle possible. It requires however high laser intensity illumination which may produce significant surface damage. Additionally it was found that the proton concentration was also affected by the UV laser irradiation resulting in modifications of the original proton exchanged waveguide structure. Finally, an alternative to UV laser irradiation as a means for PI domain engineering and waveguide formation in LN is presented. This alternative method uses visible c.w. laser irradiation and an amorphous silicon absorbing layer to couple energy into the LN crystal thus emulating the direct absorption that occurs at UV wavelengths.

Text
Zisis - Version of Record
Available under License University of Southampton Thesis Licence.
Download (7MB)

More information

Published date: March 2016

Identifiers

Local EPrints ID: 415431
URI: http://eprints.soton.ac.uk/id/eprint/415431
PURE UUID: 60f03932-9bff-4c0e-a48f-f258e4e2eed8
ORCID for Sakellaris Mailis: ORCID iD orcid.org/0000-0001-8100-2670

Catalogue record

Date deposited: 09 Nov 2017 17:31
Last modified: 14 Mar 2019 01:49

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 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.

×