Photorefractive effect in nematic liquid crystals doped with nonlinear optical chromophores

Photorefractive effect in nematic liquid crystals is attributed to reorientation of liquid crystal molecules by light induced space-charge field. In the absence of external field, nematic liquid crystals form domain structure, which is responsible for high threshold voltage. By doping nonlinear optical chromophores into liquid crystals, the threshold voltage could be reduced significantly and the mechanism involved was investigated.