A New Photorefractive Polymer/Liquid Crystal System

The photorefractive properties of PVK-based polymeric composites doped with three liquid crystals, 4OCB (4-pertyloxy-4'-cyanobiphenyl), 5OCB (4-pentyloxy-4'-cyanobiphenyl) and 8OCB (4-octyloxy-4'-cyanobiphenyl), were investigated by using the two-beam coupling experiment at 633 nm. A gain coefficient over 34 cm-1 at an applied field of 60 V/µm was observed. Among the three materials, the 8OCB-doped composite demonstrated a stronger orientational effect and the influence on charge field became apparent.