利用置放于相干系统的傅里叶交换平面的光折变晶体Cu:KnsBn在一定条件下完成了图像增强处理，由于晶体内部的位相共轭效应而在变换平面形成拉普拉斯算子.给出实验结果和扼要的理论分析。

The enhancement processing is performed by using a photorefractive crystal Cu:KNSBN placed on the Fourier transform plane of a coherent system under,cettain conditions. A Leplacian operator is formed on the transform plane because of the phase conjugation effect inside the crystal. Experimental result and a brief theoretical analysis are presented.