中心对称双光子低振幅亮屏蔽孤子的时间特性

摘要

To study the temporal properties of the low-amplitude bright spatial solitons in biased two-photon centrosymmetric photorefractive crystals,we present the expressions of the time-dependent spatial charge field and the equation of the spatial profile for the bright solitons as time evolve.The numerical results show that solitons width decreases monotonically to a minimum value toward steady state with the increasing of time.The higher the ratio of soliton peak intensity to the dark irradiation intensity,the narrower the width of bright solitons under within propagation time.The input beam can evolve the steady spatial solitons under different time.The results are benefit for improving the theory of spatial photorefractive solitons.%为了得到中心对称双光子光折变晶体中低振幅亮屏蔽孤子的时间特性的结果,推导出了晶体中空间电荷场的时间特性,得到了亮孤子的归一化空间包络随时间变化的方程.采用数值分析的方法对亮孤子的归一化空间包络及其在晶体中的时间演化特性进行了理论分析.结果表明:孤子的空间包络宽度随时间的演化单调递减一个最小值直至稳态孤子的形成;在相同的演化时间下,孤子的半峰全宽随着孤子峰值强度和暗辐射比值的增大而变小.在不同的时刻,入射光束都可在中心对称双光子光折变晶体中演化成空间孤子.所得结果对完善光折变空间孤子的理论有十分重要的意义.