Physical processes in azobenzene polymers on irradiation with polarized light

Azobenzenes can serve as model compounds for the study of trans-cis isomeri zation in more complex molecules. We have performed time-resolved spectrosc opy in solutions containing free azobenzene chromophores and diols with a v iew to obtaining the energy levels and lifetimes of the excited states. A t ransition route based on experimental results for the theoretically calcula ted energy level scheme is proposed. Physical observations of surface relie f in thin films of azobenzene polymers when irradiated with polarized light are reported. These include two beam polarization holographic observations and single beam transmission measurements through a mask, followed by atom ic force microscope and profiler investigations. It is concluded that none of the prevalent theories can explain all the observed facts.