截断光束在非Kolmogorov湍流中的扩散角及方向性  

Angular spread and directionality of truncated beams in Non-Kolmogorov turbulence

作　　者：陈晓文[1] 邓涵凌 李宾中[1] 汤明玥[1] CHEN Xiaowen;DENG Hanling;LI Binzhong;TANG Mingyue(North Sichuan Medical College,Nanchong Sichuan 637000,China)

机构地区：[1]川北医学院,四川南充637000

出　　处：《激光杂志》2019年第1期68-71,共4页Laser Journal

基　　金：四川省教育厅资助项目(No.17ZB0163);川北医学院校级科研发展计划项目(No.CBY17-A-YB03)

摘　　要：采用非Kolmogorov湍流模型,给出了截断光束在湍流中的二阶矩束宽和扩散角表达式,利用相对扩散角定量研究湍流对光束扩散角的影响,同时研究了光束在非Kolmogorov湍流中的方向性。研究表明,扩散角θsp和相对扩散角θsp/θspfree随湍流广义指数α的增大而先增大后减小,且在α=3. 11处有一个极大值;θsp/θspfree随随截断参数δ和相干参数β的增大而增大。另外,研究指出截断光束在湍流中的方向性与所采用的湍流模型无关,即不同参数的截断光束在非Kolmogorov湍流中也可具有相同的方向性。本文对重要结论给出了相关的物理解释。Based on the model of Non-Kolmogorov,the expressions of the mean-squared width and angular spread of truncated Gaussian Shell-model( GSM) beam in the turbulence are given,the influence of turbulence on the angular spread is studied quantitatively by the relative angular spread,and the directionality of the beams in the NonKolmogorov turbulence is studied. The results show that angular spread θspand relative angular spread θsp/θspfreeincrease firstly and then decrease with the increasing α,when α = 3. 11,θspand θsp/θspfreereach their maximum value.θsp/θspfreeincreases with the increasing truncation parameter δ and the coherence parameter β. In addition,it is pointed out that the directionality of truncated beam in turbulence is independent of the adopted turbulence model,i. e. the truncated beams with different parameters can also have the same directionality in Non-Kolmogorov turbulence. The main results obtained in the paper are explained physically.

关 键 词：非Kolmogorov湍流 截断光束 扩散角 方向性 

分 类 号：O436[机械工程—光学工程] TN012[理学—光学]