Model of optically induced memory in amorphous azopolymers

A phenomenological model of the light — azopolymer radiation interaction is proposed in which chromophores interact with the polymer matrix due to the mutual orientational diffusion. It is established that for some amorphous azopolymers, the model satisfactorily describes the photoinduced dichroism dynamics both at the stage of light action and relaxation, and allows the estimate of the main optical parameters of chromophores (absorption cross section and quantum yields of trans and cis isomerisations, times of the spontaneous decay of cis isomers) to be obtained by the experimentally measured dichroism. The comparison of the results of model calculations with the experimental ones shows that only a part of trans isomers participating in trans — cis isomerisation contributes to the dichroism.