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 $\mathrm{trans}\leftrightarrow \mathrm{cis}$ 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.

• Received 14 April 1997

DOI:https://doi.org/10.1103/PhysRevLett.79.2470