Fast response beam coupling in liquid crystal cells sandwiched between ZnSe substrates

Fast responses (20 ms rising time) both in symmetrical two-wave and degenerate-four-wave mixing experiments were observed and investigated in C(60) doped 4,4'-n-pentylcyanobiphenyl liquid crystal cells sandwiched between bare ZnSe substrates with an electric field applied parallel to the cell surfaces. The ZnSe material seems responsible for the fast response due to its excellent charge carrier transportation capability. Strong fanning effect and transient features were seen and studied, hinting super strong photorefractive effect in the material system. This low voltage operated liquid crystal based photorefractive approach is promising in real time applications over visible to terahertz regime.