部分相干双曲余弦高斯光束在湍流中的扩展区间

Spread Regions of Partially Coherent Cosh-Gaussian Beams in Turbulence

为探讨部分相干双曲余弦高斯光束在湍流中的扩展情况,采用湍流距离,将部分相干双曲余弦高斯光束在湍流中的传输路径划分为三个区间,并详细研究了三个区间范围随各参量的变化情况。结果显示,光束从传输路径上依次进入三个区间,其光束的扩展逐渐加剧;第一、二区间的长度及第三区间的起点均随湍流广义指数α表现出非单调变化(随α增大而先减小后增大),并随相干参数的增大而减小,随离心参数的增大而增大。此外,通过对比第一区间与瑞利区间发现,α越大,湍流在瑞利区间内对光束扩展构成的影响越容易被忽略。研究表明,选取合理的参数可有效控制部分相干双曲余弦高斯光束在湍流中的扩展区间。

To discuss the spread of partially coherent cosh-Gaussian beams in turbulence,the transmission path is divided into three regions and its variation with each parameter is studied in detail from the perspective of turbulence distance.The results show that the beams on the transmission path will enter the three regions in sequence and the beam spread will gradually become more intense;as the turbulence generalized exponent parameter becomes bigger,the length of the first region and the second region and the starting point of the third region have firstly decreased and then increased,which will also decrease with the increment of coherence parameter and increase with the enlargement of decentered parameter.In addition,it is found by comparing region I with Rayleigh region that the larger the turbulence generalized exponent parameter is,the easier it is to ignore the influence of turbulence on the beam spread in Rayleigh region.The research indicates that the spread region of partially coherent cosh-Gaussian beams in turbulence can be controlled by efficiently selecting reasonable parameters.