中文摘要：

首次研究了TM模的光折变表面波，理论上分别推导了扩散机制下的TE和TM模式的光折变表面波的非线性波方程．通过数值计算分别得到不同传播常数下两种模式光折变表面波振幅空间分布．对TM模式表面波和TE模式表面波的特性进行了比较．讨论了背景光和暗辐照等参量对TM模式表面波的影响．研究结果表明TM模表面波由于晶体各向异性使得Ex、Ez两个光波电矢量分量数值上相差较大，表面波的能量主要集中于E分量上；并且E。分量比E：分量从表面到体内振幅衰减更快速，能量被更好地约束在表面；背景光和暗辐照可明显影响TM模式光折变表面波从表面到体内的衰减速度，TM模式表面波随传播常数、背景光和暗辐照等参量的变化的规律与TE模类似．

英文摘要：

The nonlinear equations and photorefractive surface waves （PR SWs） under the TM mode with diffusion mechanism were studied for the first time. The characteristics of TE mode with that of TM mode was compared. The influences of background illumination and dark intensity were also discussed. It is found that there is great difference between the magnitude of Ex and Ez component of the PR SW and the most energy of surface wave is concentrated on the Ex component due to the anisotropic property of the medium. The decay rate of Ex is sharper than that of Ez. As a result, the energy of the PR SW is well confined to the surface. The decay rate from the surface to bulk of the medium of PR SW is clearly affected by the background illumination and dark intensity. The influence of propagation constant, background illumination and dark intensity on TM mode is analogous to that on the TE mode.