Two-beam Energy Exchange in a Hybrid Photorefractive Cholesteric Cell with a Helicoidal Polymer Network

Abstract

Two intersecting light beams illuminate cholesteric liquid crystal with helicoidal polymer network. Space-charge field of photorefractive substrate forces polymer fibrils to move and induce director grating. Coupling of light beams within the grating leads to weak beam gain coefficient greater than in solid photorefractive crystals.