Photoreversible optical data recording in films of amorphous azo dye-containing polymers

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.