Open AccessHigh-performance switchable grating based on pre-transitional effect of antiferroelectric liquid crystals
Author(s) -
Zhengyu Feng,
Ken Ishikawa
Publication year - 2018
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.26.031976
Subject(s) - optics , electric field , homeotropic alignment , materials science , diffraction efficiency , diffraction , grating , liquid crystal , diffraction grating , dielectric , ray , optoelectronics , physics , quantum mechanics
An optical phase grating prototype based on the homeotropic aligned antiferroelectric liquid crystal (AFLC) is demonstrated. By applying an in-plane electric field using comb-like electrodes, the helical structure of AFLC is deformed with the molecules rotating parallel to the electric field because of dielectric anisotropy. This deformation is called the pre-transitional effect of AFLC and induces biaxiality. By using this effect, a switchable phase grating is constructed using a 40μm thick cell filled with (S)-MHPOBC at 85°C. For 532nm TM polarized incident light, the maximum diffraction efficiency of 37.0% is achieved at the electric field of 1.8V/μm for the ± 1st order diffraction. The rise and decay times for the 1st order diffraction pattern are 510μs and 210μs, respectively. The high diffraction efficiency achieved under low field makes it promising for future electro-optical applications.