光折变介质的相位共轭波强度的近似表达式

Approximate Expressions for Intensity of the Phase Conjugate Wave in Photorefractive Media

以光折变介质中非线性耦合波微分方程的一种精确解为基础，对在推导这种精确解过程中起重要作用的一个守恒量进行讨论。通过初等变换，在不同的特殊条件下得到相位共轭波强度的几种近似表达式。与报道的其它近似方法相比，本近似方法不需要建立及求解简化的微分方程，因而具有普适。

Based on an exact solution of nonlinear coupled wave differential equations for photorefractive media, a conservative quantity which plays an important role in the process of deriving the exact solution is discussed. By elementary transformantions, several approximate expressions for intensity of the phase conjugate wave under different special conditions are obtained. As compared with other approximation methods reported, this approximation method is no need of establishing and finding solutions of reduced differential equations, therefore it is characterized by general suitability and simplicity.