Investigation of molecular alignment in poly(methyl methacrylate) polymeric thin films doped with Sudan III chromophore

Photoinduced molecular alignment in Sudan III/poly(methylmethacrylate) polymeric thin films was investigated using pump-probe method for recording the dynamics of the growing and of the relaxation of photoinduced transmission. Order parameter and dichroic ratio were investigated. Absorption characteristics upon photoinduced molecular alignment were also studied. Results showed that the excitation of Sudan III chromophore molecules by polarized light induces a reversible alignment. It was also noticed that the relationship between the order parameter and the dichroic polarization is linear in both situations of pumping and relaxation phases.