Properties Of Photosensitive Doped Nematic And Smectic Liquid Crystals And Possibility Of Their Applications

摘要

Photorefractive properties and possibility of guest-host effect application for real-time holography have been described. As the hosts isothiocyanate nematic liquid mixtures with positive dielectric anisotropy and as the guest antraquinone dyes were used. Enhancement of ultraphotorefractivity properties of these LC systems has been discussed. In dye-doped nematic liquid crystals high diffraction efficiency approaching 20 % were obtained. Fast optical grating formation with a time constant T of few ms have been observed. The results of our main investigations concentrated on the behavior of thin (5 / 20μm) cells with pure isothiocyanate nematic liquid crystal with high optical anisotropy (Δn > 0.35) and antraquinone doped have been presented. The dependence of grating formation on strength of applied dc and low frequency of ac electric field, configuration of light polarization and nematic director orientation were reported.