Photorefractive effect of photoconductive ferroelectric liquid crystalline mixtures composed of photoconductive chiral compounds and liquid crystal

The photorefractive effect in photoconductive ferroelectric liquid crystals (FLCs) that contain photoconductive chiral compounds was investigated. A series of novel photoconductive chiral compounds were synthesized. Terthiophene compounds with four chiral structures were chosen as the photoconductive chiral compounds and mixed with an achiral smectic C liquid crystal. The mixtures exhibit the ferroelectric chiral smectic C phase. The photorefractivity of the mixtures was investigated by two-beam coupling experiments. It was found that the FLCs containing the photoconductive chiral compound exhibit a large gain coefficient of 110 cm−1 and a fast response time of 5 ms.