高斯-谢尔模光束在大气湍流中传输的相干特性研究  

Investigation on coherence characteristics of Gauss-Schell model beam propagating in atmospheric turbulence

作　　者：李成强[1,2] 张合勇[1] 王挺峰[1] 刘立生[1,2] 郭劲[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,激光与物质相互作用国家重点实验室,长春130033 [2]中国科学院大学,北京100049

出　　处：《物理学报》2013年第22期187-193,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61205143)资助的课题~~

摘　　要：文章分析了高斯-谢尔光束在大气湍流中传输时相干长度的变化,并与真空传输做比较,真空传输相干长度的变化只与光源参数有关,大气湍流中传输相干长度的变化受光源参数和湍流的共同影响.真空传输光束扩展造成相干长度增大;大气湍流中,传输距离较短时,相干长度由于光源扩展而增加,当传输距离较大时,湍流效应增强引起相干长度下降.因此,单纯从相干长度方面分析大气湍流带来的影响不够完备.为排除光源扩展影响,利用相干长度与光斑尺度的比值进行分析,发现大气湍流会造成比值的下降.在数值仿真的基础上对上述结果给出了解释.The change in coherence length of Gauss-Schell model beam propagating in atmospheric turbulence is studied by comparing with propagation in free space. The coherence length change only depends on source parameters in free space while its change in turbulence is governed by source parameters and turbulence. Beam spreading results in an increase in the coherence length in vacuum. For propagation in turbulence, the coherence length increases due to beam spreading over relatively short distance while decreases on account of the enhancement of turbulence over a sufficiently long distance. Thus, the simple analysis of the influence of turbulence on the coherence length is not mature enough. In order to exclude the effect of beam spreading, the ratio of coherence length to beam size is employed. It is found that atmospheric turbulence always leads to the decline of ratio. The explanations, based on numerical simulation, of above-mentioned results are given in this paper.

关 键 词：部分相干 大气湍流 高斯-谢尔模 光束扩展 

分 类 号：O357.5[理学—流体力学] O43[理学—力学]