Open AccessPhotoinduced helical inversion in cholesteric liquid crystal cells with homeotropic anchoring
Author(s) -
Igor Gvozdovskyy,
O. Yaroshchuk,
Marina Serbina,
Rumiko Yamaguchi
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.003499
Subject(s) - homeotropic alignment , optics , materials science , liquid crystal , anchoring , rubbing , helix (gastropod) , cholesteric liquid crystal , diffraction , optoelectronics , physics , ecology , structural engineering , snail , engineering , composite material , biology
Structural changes caused by the optically induced helical inversion in the cholesteric liquid crystal cells with homeotropic anchoring are studied. In a one-step exposure, a sequence of structural transformations "lying left-handed helix - unwound homeotropic state - lying right-handed helix" is realized. In this process, smooth expansion of a left-handed helix, transition to an unwound state, emergence and smooth compression of a right-handed helix was observed. The unwound state was maintained over a rather wide range of exposures. Well-oriented and highly periodic fingerprint textures capable of the above mentioned structural changes were obtained by rubbing the aligning substrates. This allowed for obtaining photo-tunable diffraction gratings and using them to demonstrate new beam steering principle. Also, pitch reversal suggested new options for optical recording, in particular contrast reversal and edge enhancement.