Electrically controlled dynamics of energy transfer in pure nematic liquid crystals

The photorefractive effect in homeotropically aligned layer of pure nematic liquid crystal 5CB is investigated by the dynamic holographic technique. It is found the voltage controlled energy transfer between two interacting waves. The efficiency of the energy transfer, its direction and time characteristics are investigated. A surface charge-dependent photorefractive effect as well as a bulk effect determined by the molecular interaction are discussed as two complementary mechanisms of the dynamical grating recording.