Dynamic studies on laser-induced gratings in azobenzene-doped polymer film

Studies on the dynamic behaviours of laser-induced gratings through two-photon absorption and single-photon absorption were carried out in an azobenzene-doped PMMA film. The experimental results exposed the structures of energy levels and the relaxation between them, in which different lifetimes of the triplet states of trans and cis isomers of azobenzene molecule were recognized. The temporal characteristics of the diffracted signal from the induced-gratings showed also the dynamic processes of the photoisomerization reaction between two isomers.