Synthesis and Photorefractive Property of a Polymer Containing Azobenzene Group in the Side Chain

Abstract

The polyurethane (DR-PU) containing azobenzene group in the side chain was synthesized by the polycondensation reaction of Disperse Red 19 (DR19) and toluene-2,6-diisocyanate. A device consisting of the (DR-PU, PVK and C 60 ) mixture between ITO glasses was fabricated. E4, a liquid crystal, was sandwiched between the two polymer mixture films with 20-µm-thick beads as a spacer. In order to distinguish the photorefractive effect, two-beam coupling (2BC) measurement was performed. The asymmetric change of intensities of two writing beams was observed by the 2BC measurement.