LARGE STABLE PHOTOINDUCED ANISOTROPY AND OPTICAL INFORMATION-STORAGE IN LY[4'-BIS(N,N-OXYETHYLENE)IMINO-4-NITRO-AZOBENZENE SUCCINYL] FILM BY 2-WAVE MIXING

Optical information storage caused by photoinduced anisotropy in poly [4'-bis(N, N-oxyethylene) imino-4-nitroazobenzene succinyl] film is st udied by two-wave mixing. Using Nd:YAG second-harmonic pulses (100 ps) , grating of orientation of azobenzene molecules is formed in the film by photoinduced anisotropy. Up to third-order diffraction was observe d. After turning off one of the two pump lights, the signals remained. When the weaker one of two pump lights was turned off, the intensitie s of diffraction beams of another pump light almost did not decrease. The information recorded in the film can be 100% maintained for a long time (monitored over 100 days without obvious decrease).