初始波前曲率对强非局域介质中光束演化的影响  

Influence of Phase-Front Curvature for an Optical Beam in Strongly Nonlocal Media

作　　者：王玉青[1] 钟东洲[1] 黄东[1] 

机构地区：[1]五邑大学信息工程学院,广东江门529020

出　　处：《光学学报》2010年第8期2377-2382,共6页Acta Optica Sinica

基　　金：广东高校优秀青年创新人才培育项目(30717003)资助课题

摘　　要：通过变分法,研究了在真实的非局域介质中当响应函数为e指数衰减型时具有初始波前曲率的光束的传输特性,并得到了光束各参数演化的解析解。研究发现,不论初始输入功率大小如何,正的初始波前曲率均会导致光束先展宽,而负的初始波前曲率则导致光束先压缩。对于具有不同初始波前曲率的光束,在某一确定的输入功率处,其束宽的演化曲线周期性的相交,而这些交点处恰是无初始波前曲率的光束压缩或展宽的极值处,通过和Snyder等提出的强非局域孤子模型的结果进行了比较,发现这种现象是Snyder-Mitchell的线性模型中所不存在的。The evolution of the optical beam with initial phase-front curvature is studied in the strongly nonlocal nonlinear media with exponential-decay response.The analytical solutions are obtained by employing the variational approach.It is found that no matter how high the input power is,the beam is initially expanded for the positive phase-front curvature,and initially contracted for the negative phase-front curvature.For a fixed input power,the curves of the beam width with different initial phase-front curvatures intersect periodically,and interestingly,at these very cross points the optical beams with zero phase-front curvatures happen to either expand to its maximum or contract to its minimum,which do not exist in the Snyder-Mitchell linear model through the comparison between our model with Snyder＇s strong nonlocal solitions model.

关 键 词：非线性光学 非局域非线性薛定谔方程 变分法 空间光孤子 波前曲率 

分 类 号：O437.5[机械工程—光学工程]