Photorefractive properties of Cu-doped (K0.5Na0.5)(0.2)(Sr0.75Ba0.25)(0.9)Nb2O6 crystals with different doping levels and different dimensions

In this article, we studied the photorefractive properties of Cu-doped (K0. 5Na0.5)(0.2)(Sr0.75Ba0.25)(0.9)Nb2O6 (Cu:KNSBN) crystals with different dop ing levels. The properties include two-wave mixing and self-pumped phase co njugation, absorption properties, and the growth conditions as well. We als o studied the effect of the dimensions on the photorefractive properties. T he mechanism of Cu-doped KNSBN and the influence of the different sites occ upied by Cu+ on photorefractive properties are also discussed. All the expe rimental results showed that doping levels have much effect on the photoref ractive properties. The crystal with a higher doping level has a higher eff ective charge carrier density, a larger coupling coefficient, and a faster response rate, which is suitable for fast optical information processing. D imension has much influence on the photorefractive properties. The thinner crystal with the same doping level has a larger coupling gain coefficient, and a shorter response time. (C) 1999 American Institute of Physics. [S0021 -8979(99)07418-6].