Photoinduced Orientation and Holographic Recording in Polyester Films Comprising Azobenzene Side-Groups Using 633 nm Red Light

New liquid crystalline polyesters comprising azobenzene side groups are synthesized to compare liquid crystalline nature of the materials and to investigate the photoinduced orientation behavior using linearly polarized (LP) 633 nm red light. Because of the axis-selective Z-to-E photoisomerization of the azobenzene moieties, the irradiating with a LP 633 nm light to a Z-isomer film induces a molecular reorientation parallel to the polarization of the light, which generates a positive optical anisotropy of the film. A polarization holography of a Z-isomer film using orthogonally polarized 633 nm light is presented.