Calculation of the efficiency of polarization-insensitive surface-stabilized ferroelectric liquid-crystal diffraction gratings

Abstract

A rigorous analysis is presented of the diffraction efficiency of a polarization-insensitive surface-stabilized ferroelectric liquid-crystal (SSFLC) phase grating, taking full account of the internal structure of the ferroelectric liquid-crystal layer. When no field is applied, the twisted director profile in the relaxed state gives an optimum diffraction efficiency for a device thickness between the half-wave-plate and the full-wave-plate conditions. The influence of the magnitude of the spontaneous polarization and applied ac fields are investigated, and it is shown that the diffraction efficiency of a binary SSFLC phase grating can be strongly enhanced with the technique of ac stabilization.

Beam-splitter switches based on zenithal bistable liquid-crystal gratings

“…In this work, we demonstrate switchable beam splitting in ZB optical diffraction gratings (DGs). Liquid-crystal tunable diffractive gratings have been thus far demonstrated using different tuning mechanisms, such as the electro-optical effect [24][25][26][27][28], tunable photoalignment [29][30][31], and all-optical switching via the illumination of azo-dye LC mixtures [32][33][34]. The proposed LC-ZB-DG relies on the electro-optic switching mechanism, thus resulting in zero idle and very low switching power consumption, as well as fast switching speeds.…”

Influence of a helical pitch on orthoconic antiferroelectric liquid crystals performance

“…Such mate− rials are usually aligned using conventional method tech− niques. In this case, the liquid crystal director is aligned in the nematic phase, which results in uniform alignment of the smectic layers in the SmA phase, during a cooling into the SmC*, consequently the smectic layers tilt form a chevron structure because of layer shrinkage, this results in the decrease in the device efficiency [6,7]. Polarization−insensi− tive ferroelectrics for binary phase modulation require ferro− electric liquid crystal with a tilt angle 45°, filled in a cell with a thickness giving half wave plate at the operation wavelength [8,9].…”

Design of a Polarization-Insensitive Diffraction Grating Device Based on a Dye-Doped Liquid Crystal in Polymer Networks

“…Most of the LC gratings possess the polarization-dependent diffraction that results in overall system losses. In order to solve this problem, the spatial light modulator based on ferroelectric liquid crystals (FLCs) showing two stable states has been recently proposed [5][6][7]. However, such approach inevitably involves the complexity in patterned electrodes and the difficulty in uniform alignment of the FLCs.…”