Photoinduced anisotropy of the refractive index of an azopolymer with liquid-crystal properties

The formation of a photoinduced refractive-index grating in a photosensitive azopolymer with liquid-crystal (LC) properties is theoretically studied. Equations for photoinduced additions to the refractive index of the LC and amorphous polymers are obtained from balance equations for the distribution densities of trans- and cis-isomers of azodyes. The frequency characteristics of the response of the refractive index to a harmonic perturbation are calculated for different values of the LC order parameter.