研究了部分相干厄密高斯光束沿不同湍流路径的偏振保持.发现相干长度越大,光束阶数m, n越大,偏振随距离改变越小.当天顶角ξ<π/4,在斜程下行路径中极化的演化与无湍流空间一致.长距离通信时,在水平路径中极化的演化与无湍流空间、斜程路径中差异较大.该结论可更有效的选择传输路径,对多自由度空间通信实现具有指导意义.

The properties of polarization preservation of partially coherent Hermite-Gaussian beams propagating along different atmospheric turbulence paths were studied. The analytical expressions for the polarization of partially coherent Hermite-Gaussian beams propagating through atmospheric turbulence along different paths have been derived. It is shown that the larger the coherence length is, and the larger the beam order m, n are, the less the polarization is changed. We found that the evolution properties of the polarization in slant-down paths through turbulent atmosphere are similar to the case in free space if the condition zenith angle ξ<π/4 is satisfied. While at a long propagation distance, evolution properties of polarization in horizontal paths of turbulent atmosphere differs much from those in free space and in slant paths. The results may allow one to choose the optimal propagation path in terms of specific applications, which is helpful for future experimental implementation of multiple-degrees-of-freedom free-space communication.