Light-controlled polarization switches in azobenzene-containing polymers

Three new side-chain cyan-azopolymers have been synthesized for the purposes of optical storage and processing of information. A very large birefringence (> 0.05) is induced in them on illumination with linearly polarized Ar laser beam (lambda = 488 nm). It has been shown that the value of the photoinduced birefringence depends on the length of the side chains of the polymers. The effect has long memory time - more than six months. We have used the self-induced rotation of the polarization ellipse in photobirefringent materials to induce chiral structures in the polymers. Total twist angles of the photoinduced spirals more than 90degrees have been achieved. The new polymers are suitable for the fabrication of light-controlled polarization switches.