Optical information storage caused by photoinduced anisotropy in poly[4'-bis(N,N-oxyethylene)imino-4-nitroazobenzene succinyl]film is studied by two-wave mixing.Using Nd:YAG second-harmonic pulses(100ps),grating o...Optical information storage caused by photoinduced anisotropy in poly[4'-bis(N,N-oxyethylene)imino-4-nitroazobenzene succinyl]film is studied by two-wave mixing.Using Nd:YAG second-harmonic pulses(100ps),grating of orientation of azobenzene molecules is formed in the film by photoinduced anisotropy.Up to third-order diffraction was observed.After turning off one of the two pump lights,the signals remained.When the weaker one of two pump lights was turned off,the intensities 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).展开更多
4[4’-(phenylazo)phenylazo]phenol was synthesized and characterized. Optical-induced Freedericksz transition of 5CB liquid crystal doped with trace diazophenyl was studied. It was observed that the doped 5CB dramatica...4[4’-(phenylazo)phenylazo]phenol was synthesized and characterized. Optical-induced Freedericksz transition of 5CB liquid crystal doped with trace diazophenyl was studied. It was observed that the doped 5CB dramatically decreased the optical field threshold, and the Freedericksz transition threshold occurred at optical intensity level of 0.3 mW/mm2 for the 12.5 μm thickness planar alignment doped 5CB, which is three orders of magnitude lower than that for the pure 5CB. This new phenomenon indicated that trans-cis isomerization of diazophenyl plays an important role in the decrease of the Freedericksz transition threshold.展开更多
文摘Optical information storage caused by photoinduced anisotropy in poly[4'-bis(N,N-oxyethylene)imino-4-nitroazobenzene succinyl]film is studied by two-wave mixing.Using Nd:YAG second-harmonic pulses(100ps),grating of orientation of azobenzene molecules is formed in the film by photoinduced anisotropy.Up to third-order diffraction was observed.After turning off one of the two pump lights,the signals remained.When the weaker one of two pump lights was turned off,the intensities 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).
基金the National Natural Science Foundation of China (Grant No. 19474073) and the Natural Science Foundation of Guangdong Province (Grant No. 980346).
文摘4[4’-(phenylazo)phenylazo]phenol was synthesized and characterized. Optical-induced Freedericksz transition of 5CB liquid crystal doped with trace diazophenyl was studied. It was observed that the doped 5CB dramatically decreased the optical field threshold, and the Freedericksz transition threshold occurred at optical intensity level of 0.3 mW/mm2 for the 12.5 μm thickness planar alignment doped 5CB, which is three orders of magnitude lower than that for the pure 5CB. This new phenomenon indicated that trans-cis isomerization of diazophenyl plays an important role in the decrease of the Freedericksz transition threshold.
