Mean-field theory of photoinduced molecular reorientation in azobenzene liquid crystalline side-chain polymers

A novel mean-field theory of photoinduced reorientation and optical anisotropy in liquid crystalline side-chain polymers is presented and compared with experiments, The reorientation mechanism is based on photoinduced trans <-> cis isomerization and a multidomain model of the material is introduced. The theory provides an explanation for the high long-term stability of the photoinduced anisotropy as well as a theoretical prediction of the temporal behavior of photoinduced birefringence. The theoretical results agree favorably with measurements in the entire range of writing intensities used experimentally.