Photoinduced surface relief grating formation using new polymers containing the same azobenzene chromophore as a photochoromic amorphous molecular material

Abstract

In order to gain an insight into the relationship between the structure of polymer main chain and photoinduced surface relief grating (SRG) formation, new vinyl, acrylate, and methacrylate polymers containing the same azobenzene chromophore as a photochromic amorphous molecular material were designed and synthesized. Comparative studies of photoinduced SRG formation using these new polymers together with the parent amorphous molecular material showed that the rate of SRG formation increased in the order: the vinyl polymer<the methacrylate polymer<the acrylate polymer<the parent amorphous molecular material, while the diffraction efficiency and modulation depth of resulting SRG increased in the order: the parent amorphous molecular material<the vinyl polymer<the acrylate polymer<the methacrylate polymer. These results can be explained by means of the flexibility of the azobenzene chromophore depending upon the structure of polymer main chain and the glass-transition temperatures of the materials.