湍流大气中空间部分相干奇异光波的传输

Propagation of partially coherent singularity beams in turbulent atmosphere

自由空间中带有光学涡的部分相干光的传输特性是影响大气光通信系统性能的关键因子之一.基于弱湍流大气中光波传输的 Rytov 方法和部分相干光的互相干函数的交叉谱密度函数近似,研究了带有"光学涡"的空间部分相干拉盖尔-高斯光束在湍流大气中的传输特性,得出了弱湍流大气中传输的部分相干光束互相干函数和平均光强空间分布的解析关系.研究结果表明,弱湍流大气起伏仅仅影响这类光束相干函数的幅值,不改变光束光学涡的分布特征.

The propagation properties of the partially coherent singularity beams through atmospheric turbulence are key effect-factors of atmospheric turbulence on free space optical communications systems.Based on the Rytov approximation and the approximation of cross-spectral density for the mutual coherence function of the partially coherent field,the propagation properties of the partially coherent Laguerre-Gauss beams with optical vortices in turbulent atmosphere are discussed.Expressions for average intensity and the mutual coherence function of partially coherent field when beams propagation in weak turbulent atmosphere are obtained from the cross-spectral density function.It is shown that the vortex structure of the average cross-spectral ,density of partially coherent Laguerre-Gauss beams has the same helicoidally shape with that of the phase of the fully coherent Laguerre-Gauss beam,which is propagation in free space,and the relative intensity of the beam is degraded by optical vortex.