Synthesis and characterization of bi-functional photorefractive polymers

A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized, in which azo derivatives as electro-optic chromophores and carbazolyl as photoconductive moiety were covalently linked on the acrylate backbone. Photorefractive experiments showed that a high two-beam coupling gain coefficient of 93 cm−1, diffraction efficiency of 12% and electro-optic coefficient of 26 pm/V were obtained. With increasing writing beamʹs intensity, the two-beam coupling enhanced gradually, and then reached saturation. Using the method of four-wave mixing, the photoisomerization grating was observed.