Jull, EIL orcid.org/0000-0003-3228-1348 and Gleeson, HF orcid.org/0000-0002-7494-2100 (2019) Novel devices with photosensitive elements. In: Proceedings of SPIE - The International Society for Optical Engineering. SPIE OPTO 2019, 02-07 Feb 2019, San Francisco, USA. Society of Photo-optical Instrumentation Engineers ISBN 9781510625242
Abstract
Liquid Crystal (LC) devices with photosensitive elements have incredible scope for creating unique photo-induced optical devices. The use of azobenzene based materials, which undergo a trans-cis isomerisation when irradiated with light of a specific wavelength, is firmly established in LC research. The trans conformation is an elongated rod-like shape, similar to LC mesogens, whilst the cis conformation is closer to a spherical (bent) shape, disrupting to the LC order. When these materials are doped into LC materials they are able to produce light induced responses, and therefore their application to photo-switchable optics and devices is undeniable. In this research paper the light induced order modification, rather than light induced reorientation, is utilized to produce an all-optical switchable laser protection device. Upon irradiation of an azo-doped LC system with a continuous, low power (0.5 mW), laser threat (λ=405 nm) the transcis photoisomerisation process is triggered. This results in the trans-cis conformal shape change, lowering of the LC order, and causing the system to switch from the LC nematic phase (transmitting between crossed polarisers) to the isotropic liquid phase (blocking/dark between crossed polarisers). The optical properties of the azo-doped LC materials have been characterized and the response time dependence on azo-dopant concentration, system temperature, and laser threat intensity is thoroughly investigated.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 Society of Photo‑Optical Instrumentation Engineers (SPIE). This is an author produced version of a paper published in Proceedings of SPIE - The International Society for Optical Engineering. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Soft Matter Physics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 06 Sep 2019 13:56 |
Last Modified: | 06 Sep 2019 13:56 |
Status: | Published |
Publisher: | Society of Photo-optical Instrumentation Engineers |
Identification Number: | 10.1117/12.2515807 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:150483 |