Optical Information Storage in Poly[3'-Methyl-4'-Bis(N,N-Oxyethylene)Imino-4-Nitro-Azobenzene Sebacoyl] Film by Degenerate Four-Wave Mixing

Optical storage caused by photo-induced anisotropy in poly[3'-methyl-4'-bis(N,N-oxyethylene)imino-4-nitro-azobenzene sebacoyl] film is studied by degenerate four-wave mixing. Molecule orientation gratings which are stable for three months are produced. The grating in the sample can be "erased" by using circular polarized light. So an azobenzene polymer thin film can be used many times to restore optical information.