The photorefractive effect in polymeric systems

The review concerns the photorefractive effect in polymeric systems, which involves the creation, upon a primary photochemical reaction, of a phase grating shifted in space relative to the fringe pattern. The interaction of interfering laser beams accompanied by energy transfer from one beam to the other as well as salient features of the refractive index modulation in polymeric systems with low and high glass transition temperatures are considered. Particular attention is given to the photorefractive polymers with high glass transition temperatures containing nanocrystalline J-aggregates of cyanine dyes, which are characterised by high third-order nonlinear electric susceptibilities and induce modulation of the refractive index due to the Kerr electrooptic effect. The prospects for application of polymeric photorefractive materials are outlined.