电磁反常涡旋光束在各向异性大气湍流中的偏振特性

Polarization properties of electromagnetic anomalous vortex beam in anisotropic atmospheric turbulence

本文研究了部分相干电磁反常涡旋光束(PCEAVB)通过各向异性non-Kolmogorov大气湍流后的偏振度和偏振态的变化。研究结果表明,PCEAVB的偏振度分布为同心的圆环,而随着光束阶数n和拓扑荷数m的增大,同心圆环数逐渐增加,分布越密集。光束阶数n越高、拓扑荷数m越低,高偏振度分布区域越趋于中间区域;反之,则趋于外环分布。PCEAVB的偏振态随着传输距离z的增加由均匀线偏振变成非均匀线偏振,偏振角呈现圆环状分布,且偏振角较大的区域随着传输距离z的增大而逐渐向外环移动。拓扑荷数m越大、光束阶数n越小,PCEAVB的偏振角较大的区域越靠近于中心区域。而且光束阶数n和拓扑荷数m越大的PCEAVB,偏振态受到湍流的影响越小。且各向异性越强的大气湍流对PCEAVB的影响越小,光束演化得越慢。

We have studied the degree of polarization(DOP)and the state of polarization(SOP)of partially coherent electromagnetic anomalous vortex beam(PCEAVB)through anisotropic non-Kolmogorov atmospheric turbulence.The results show that the distributions of DOP present concentric ring,and the number of concentric rings will increase with the increasing of beam order n and topological charge m.And the relative high DOP distribution region tends to the middle region with the increasing of beam order n and the decreasing of topological charge m,otherwise,it tends to the outer ring distribution.We can also find that the SOP distributions of PCEAVB will change from uniform linear polarization into nonuniform linear polarization with the increasing of propagation distance z,and the polarization angle shows the circular distribution.And the region with large polarization angle gradually moves to the outer ring with the increasing of propagation distance z.The big polarization angle region of PCEAVB with the bigger topological charge m and smaller beam order n is closer to the central region.Moreover,the larger beam order n and topological charge m,the less influence of atmospheric turbulence on the SOP of PCEAVB.It can be also found that PCEAVB is less effected by the non-Kolmogorov atmospheric turbulence with strong anisotropy and the beams will evolve more slowly.