基于扩散效应, 研究了启动光强对双光子光伏光折变介质中亮光伏空间孤子自偏转特性的影响, 将亮光伏孤子作为入射孤波, 采用数值方法求解含扩散项的波演化方程。结果表明: 随着启动光强度的加大, 孤子强度的半峰全宽逐渐增加; 孤子中心的自偏转距离随着启动光强的加大开始有所增加, 达到一定值后, 随着启动光强的继续加大而逐渐减小, 得到孤子中心自偏转距离与启动光强之间的非线性关系源于孤子半峰全宽和扩散项二者的共同作用的结论。

Gating beam intensity effect on the self-deflection of bright photovoltaic spatial solitons in two-photon photovoltaic photorefractive media was numerically investigated based on diffusion effect. Taking the bright photovoltaic solitons as the input solitary beam, the beam propagation equation was numerically solved in which the diffusion term was taken into account. The full width of half maximum (FWHM) of solitons intensity profile increases with gating beam intensity. The distance of self-deflection of solitons increases with gating beam intensity and starts to decrease when gating beam intensity is increased over a specific value. The nonlinear relation between self-deflection distance and gating beam intensity results from the effects of FWHM and diffusion term.