PHOTOREFRACTIVE MATERIAL KNSBN - CU

This paper reports systematically the crystal growth and photorefracti ve properties of Cu-doped KNSBN, and the mechanism of the Cu ions' eff ects on the photorefractive properties of KNSBN. The Cu ions doped in KNSBN can form two energy levels in the band gap, thus play important roles in the photorefractive process. They increase the effective elec tron combination center concentration, which results in the modificati on of the photorefractive properties of KNSBN. The two-wave coupling g ain coefficient of KNSBN:Cu is two times greater than that of KNSBN. T he photorefractive sensitivity of Cu-doped KNSBN is estimated to be in the order of 10(-3) cm2/J. Its cat-SPPC reflectivity can reach 65% co rresponding to an response time less than 8 s.