海洋湍流中部分相干环状光束的空间相干性  

Spatial Coherence of Partially Coherent Annular Beams in Oceanic Turbulence

作　　者：蒲欢[1] 季小玲[1] 杨婷[1] 

机构地区：[1]四川师范大学物理系,四川成都610068

出　　处：《光学学报》2015年第A01期8-13,共6页Acta Optica Sinica

基　　金：国家自然科学基金（61475105）

摘　　要：基于广义惠更斯一菲涅耳原理，推导出了部分相干环状光束在海洋湍流中传输时光束相干度的解析公式，详细研究了光束相干度以及相干度宽度随传输距离、海洋湍流参数和光束参数的变化。研究结果表明：部分相干环状光束在自由空间和弱海洋湍流中传输时其光束相干度会出现振荡现象，但随着海洋湍流增强最终趋于类高斯分布。在弱海洋湍流情况下，光束相干度宽度在某一传输距离处达到极大值，并且它与环状光束遮拦比和光束相干参数有关。但是，在强海洋湍流情况下，光束遮拦比和相干参数对光束相干度的影响不大。所得结果对工作于水下湍流环境中的部分相干环状光束的应用具有意义。Based on the extended Huygens-Fresnel principle, the analytical expression for the coherence degree of partially coherent annular beams propagating through oceanic turbulence is derived. The changes of the coherence degree and the width of the coherence degree of partially coherent annular beams versus the propagation distance, the oceanic turbulence parameters and the beam parameters are investigated in detail. It is shown that the oscillatory behavior of the coherence degree may appear with partially coherent annular beams propagating in free space or weak oceanic turbulence, but the coherence degree takes a Gaussian-like profile as the strength of oceanic turbulence increases. On the other hand, under weak oceanic turbulence condition, the width of the coherence degree reaches a maximum at a certain propagation distance, which depends on the obscure ratio and the correlation parameter of annular beams. However, under strong oceanic turbulence condition, the coherence degree is nearly independent of the obscure ratio and the correlation parameter of annular beams. The results are useful for applications of partially coherent annular beams in oceanic turbulence.

关 键 词：海洋光学 相干度 海洋湍流 部分相干环状光束 相干度宽度 

分 类 号：O436[机械工程—光学工程]