The University of Southampton
University of Southampton Institutional Repository

100 GHz electrically tunable planar Bragg grating via nematic liquid crystal overlay towards reconfigurable WDM networks

100 GHz electrically tunable planar Bragg grating via nematic liquid crystal overlay towards reconfigurable WDM networks
100 GHz electrically tunable planar Bragg grating via nematic liquid crystal overlay towards reconfigurable WDM networks
Novel liquid crystal-based integrated optical devices with >140GHz electrical tuning are presented for application towards reconfigurable wavelength division multiplexing (WDM) networks. Initial results with Bragg wavelength tuning covering five 25GHz WDM channel spacing have been achieved with 170V (peak-to-peak) sinusoidal voltages applied across electro-patterned ITO-covered glass electrodes placed 60µm apart. These prototype devices were fabricated using direct UV grating writing, with an evanescent field coupling into a liquid crystal overlay through an etched window. Electrically controlled liquid crystal birefringence modifies the waveguide effective index, resulting in Bragg wavelength shift. Merck 18523 nematic liquid crystals are used, exhibiting compatible refractive index values to that of silica (no=1.44, ne=1.49 at lambda=1550nm). Homeotropic alignment of the liquid crystal is provided by application of a surfactant layer.

The inherent refractive index sensitivity of our etched direct-UV-written structures allows observation of previously unreported liquid crystal surface-behaviour, such as multi-threshold points during variation of the applied field. Continued optimisation based on evanescent field penetration, electrode layout, and surface interaction will allow implementation towards a variety of novel liquid crystal applications and devices. For example, a cascaded architecture of these integrated liquid crystal devices operating at different Bragg wavelengths would pave the way towards true colorless add/drop modules for dense optical networks.
liquid crystal, planar bragg gratings, direct uv writing, tunable optical devices, reconfigurable optical networks
Adikan, Faisal Rafiq Mahamd
cc750260-56c2-4739-b863-d087a9599088
Gates, James C.
b71e31a1-8caa-477e-8556-b64f6cae0dc2
Major, Huw E.
b6df0066-f28b-498f-b606-bf3f4421fa94
Gawith, Corin B.E.
926665c0-84c7-4a1d-ae19-ee6d7d14c43e
Smith, Peter G.R.
8979668a-8b7a-4838-9a74-1a7cfc6665f6
Dyadyusha, Andriy
daa939a8-2860-4a31-ab12-7950bf59aeef
Kaczmarek, Malgosia
408ec59b-8dba-41c1-89d0-af846d1bf327
Sparrow, Ian J.G.
ef0af264-8a21-4380-b082-25db946fd6d2
Adikan, Faisal Rafiq Mahamd
cc750260-56c2-4739-b863-d087a9599088
Gates, James C.
b71e31a1-8caa-477e-8556-b64f6cae0dc2
Major, Huw E.
b6df0066-f28b-498f-b606-bf3f4421fa94
Gawith, Corin B.E.
926665c0-84c7-4a1d-ae19-ee6d7d14c43e
Smith, Peter G.R.
8979668a-8b7a-4838-9a74-1a7cfc6665f6
Dyadyusha, Andriy
daa939a8-2860-4a31-ab12-7950bf59aeef
Kaczmarek, Malgosia
408ec59b-8dba-41c1-89d0-af846d1bf327
Sparrow, Ian J.G.
ef0af264-8a21-4380-b082-25db946fd6d2

Adikan, Faisal Rafiq Mahamd, Gates, James C., Major, Huw E., Gawith, Corin B.E., Smith, Peter G.R., Dyadyusha, Andriy, Kaczmarek, Malgosia and Sparrow, Ian J.G. (2007) 100 GHz electrically tunable planar Bragg grating via nematic liquid crystal overlay towards reconfigurable WDM networks. SPIE Europe Optics & Optoelectronics. 16 - 20 Apr 2007. 1 pp . (doi:10.1117/12.722883).

Record type: Conference or Workshop Item (Paper)

Abstract

Novel liquid crystal-based integrated optical devices with >140GHz electrical tuning are presented for application towards reconfigurable wavelength division multiplexing (WDM) networks. Initial results with Bragg wavelength tuning covering five 25GHz WDM channel spacing have been achieved with 170V (peak-to-peak) sinusoidal voltages applied across electro-patterned ITO-covered glass electrodes placed 60µm apart. These prototype devices were fabricated using direct UV grating writing, with an evanescent field coupling into a liquid crystal overlay through an etched window. Electrically controlled liquid crystal birefringence modifies the waveguide effective index, resulting in Bragg wavelength shift. Merck 18523 nematic liquid crystals are used, exhibiting compatible refractive index values to that of silica (no=1.44, ne=1.49 at lambda=1550nm). Homeotropic alignment of the liquid crystal is provided by application of a surfactant layer.

The inherent refractive index sensitivity of our etched direct-UV-written structures allows observation of previously unreported liquid crystal surface-behaviour, such as multi-threshold points during variation of the applied field. Continued optimisation based on evanescent field penetration, electrode layout, and surface interaction will allow implementation towards a variety of novel liquid crystal applications and devices. For example, a cascaded architecture of these integrated liquid crystal devices operating at different Bragg wavelengths would pave the way towards true colorless add/drop modules for dense optical networks.

Text
3569.pdf - Other
Download (68kB)

More information

Published date: 2007
Additional Information: Conference code: COO108
Venue - Dates: SPIE Europe Optics & Optoelectronics, 2007-04-16 - 2007-04-20
Keywords: liquid crystal, planar bragg gratings, direct uv writing, tunable optical devices, reconfigurable optical networks
Organisations: Optoelectronics Research Centre

Identifiers

Local EPrints ID: 46136
URI: https://eprints.soton.ac.uk/id/eprint/46136
PURE UUID: 8356bf00-b056-47fd-8112-32779cc1dbad
ORCID for James C. Gates: ORCID iD orcid.org/0000-0001-8671-5987
ORCID for Corin B.E. Gawith: ORCID iD orcid.org/0000-0002-3502-3558

Catalogue record

Date deposited: 24 May 2007
Last modified: 14 Mar 2019 01:48

Export record

Altmetrics

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.

×