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The photoreversible properties of films of amorphous azo-containing polymers (AAPs) are studied theoretically and experimentally. The control of the sign of a photoinduced addition Δnind to the refractive index of the polymer by changing polarisation of the incident light is demonstrated. A theoretical model of photoinduced processes in AAP films is proposed, which takes into account the orientation diffusion of trans-isomers of azo dyes, and simplified analytic approaches describing the photoorientation dynamics in AAPs are considered. The theoretical results are in good agreement with our experimental data.

The dynamics of two-wave mixing in a film of azocontaining photosensitive polymer with liquid-crystal properties is studied experimentally and theoretically. A simplified theoretical model is proposed for the energy exchange between light beams in a polymer layer taking into account absorption, saturation, and diffusion in the polymer. The theoretical results obtained in the approximations of the chosen model are in good agreement with the experimental data. The dynamic characteristics of an interferometer based on two-wave mixing in a film of photosensitive polymer are studied and the possibility of adaptive compensation of slow phase fluctuations in one of its arms is demonstrated.

The dynamics of holographic recording in a film of azo-containing liquid-crystal polymer is studied both experimentally and theoretically in the presence of the orienting electric field. The possibility is demonstrated to efficiently control the optical recording regime by varying the applied field. The specificity of hologram formation in the case of different polarisation of the interacting light beams is considered. A theoretical model describing the holographic recording dynamics in a film of azo-containing nematic polymer is presented; numerical simulation of the processes of recording and read-out in anisotropic holograms is carried out as well.