研究了无耗晶体的扩散效应对高斯光束在光伏光折变晶体中孤波演化特性的影响.结果表明,对于给定的与晶体参量匹配的高斯光束,晶体的扩散效应将造成高斯光束孤波演化的自偏转,而且其自偏转过程与同参量的屏蔽光伏明孤子的自偏转过程具有极其类似的特征.同时发现,高斯光束的波形即光束的横截面对其孤波演化的自偏转影响最大.比较了高斯光束孤波演化的自偏转与明孤波自偏转的理论曲线,结果表明,对于匹配的高斯光束,其自偏转程度与解析计算结果非常接近.

The impact of the diffusion effect within the lossless photovotaic photorefractive crystal on the solitary wave evolution of a Gaussian beam is theoretically investigated. The result obtained indicates that, for a given photovotaic photorefractive crystal and a Gaussian beam which matches with its parameters, the diffusion effect can cause self deflection for the solitary wave evolution during the transmission of the incident Gaussian beam (which moves on a parabolic trajectory), and the self deflection process is extremely similar to that of a screening photovoltaic bright soliton with the same parameters. it is also found that the cross section of a Gaussian beam has the maximal influence on its solitary wave evolution. A comparision of the self defection of a Gaussian beam with the result calculated theoretically for a bright soliton shows that, for the corresponding matched Gaussian beam, its self deflection extent is quite close to the result of theoretical calculation.