Open AccessPhoto-switchable bistable twisted nematic liquid crystal optical switch
Author(s) -
Chun-Ta Wang,
YuehChi Wu,
TsungHsien Lin
Publication year - 2013
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.004361
Subject(s) - liquid crystal , bistability , polarizer , materials science , optics , shutter , optical switch , dopant , optical bistability , optoelectronics , twist , photoisomerization , doping , nonlinear optics , birefringence , physics , laser , isomerization , chemistry , biochemistry , geometry , mathematics , catalysis
This work demonstrates a photo-switchable bistable optical switch that is based on an azo-chiral doped liquid crystal (ACDLC). The photo-induced isomerization of the azo-chiral dopant can change the chirality of twisted nematic liquid crystal and the gap/pitch ratio of an ACDLC device, enabling switching between 0° and 180° twist states in a homogeneous aligned cell. The bistable 180° and 0° twist states of the azo-chiral doped liquid crystal between crossed polarizers correspond to the ON and OFF states of a light shutter, respectively, and they can be maintained stably for tens of hours. Rapid switching between 180° and 0° twist states can be carried out using 408 and 532 nm addressing light. Such a photo-controllable optical switch requires no specific asymmetric alignment layer or precise control of the cell gap/pitch ratio, so it is easily fabricated and has the potential for use in optical systems.