We synthesized new chromophores that have modified structures of DMNPAA. Among them, a 4-butoxy-3-propyl-1-(4?-nitrophenyazo)benzene composite improves the response speed quite well. We obtained the reorientation time constant of 19ms (@54V/?m), which is 2,300 times faster than of DMNPAA at room temperature. The speedup of orientational response is caused by the improvement of dispersivity in the polymer composite and the decrease of glass transition temperature. The temperature dependence of photorefractive properties of poly(N-vinlycarbasole) (PVK)-based composite is studied in the temperature range of 5-60°C. The experimental results show that the reorientation speed increases with the increase of temperature. The diffraction efficiency first increases with the increase of temperature, and then decreases as temperature is further increased.
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