Dynamics of optically induced dichroism (theory and experiment)

The dynamics of photoinduced dichroism has been experimentally and theoretically (on the basis of the Dumont model) investigated in several ridge-shaped azopolymers. This dynamics was used to reconstruct the dynamics of change in the concentration of trans-isomers and anisotropy of their angular distribution, thickness-averaged for optically thick samples. It is shown that, at the beginning of illumination, the experimental dependences of dichroism are described well within the Dumont model, even disregarding the orientational memory, on the assumption that only some part of trans-isomers are involved in trans-cis isomerization.