光折晶体Cu:KNSBN的双光束耦合——能量转移研究

Experimental Investigation on Holographic Intormation Storage in Photorefractive Crystal Cu-Doped KNSBN II . a Study on the Energy Transfer in Two Wave Coupling

二波耦合是研究光折晶体特性和品质的一种重要方法。本文着重分析基于光析变理论的二波耦合能显转移原理,研究所得的Cu:KNSBN晶体的增益系数γ与两光束入射角20的关系,以及ρ与光束比β的关系曲线。测量结果显示:Cu:KNSBN晶体具有大的τ值。最后,本文还报告了该晶体的高频时间调制传输特性,以及测得的衍射效率η与光束夹角20及调制频率f的关系曲线。

Two wave coupling is an important method to investigate the characteristics and qualities of photorefractive crystal.This paper represents our results, measured , based on the principle of energy transfer in two wave coupling which is included in the theory of photorefractive effect, for the relationship between the gain coefficient of two wave coupling F and the crossing angle of the beam 29, and also r as a function of beam ratio p. The results indicate that F of the Cu:KNSBN crystal is big. At last, high frequency temporal modulation characteristics of this crystal bulk and the function of diffraction efficiency as the crossing angle of the beam 29 and the frequency of modulation f are described respectively.