Photo-induced birefringence in a liquid crystalline azobenzene side-chain polymer without the trans-cis photoisomerization

Summary form only given. Recently polymeric materials have been suggested as the most promising materials for optical data storage applications. The liquid-crystalline side-chain polymers, in particular, are intensively studied because of their highly-induced birefringence and reversibility in data storage. In general, the process of the optical storage in liquid-crystalline azobenzene polymers can be understood by photoinduced birefringence or dichroism which are due to the alignment of the mesogenic groups in the polymer toward a perpendicular direction to the direction of polarization of an irradiating light.