大气湍流对部分相干厄米-高斯光束空间相干性的影响

基于广义惠更斯-菲涅耳原理，并采用Rytov相位结构函数二次近似，推导出了部分相干厄米-高斯(H-G)光束通过大气湍流传输的光谱相干度公式，研究了湍流对光束的空间相干特性的影响.研究表明，部分相干H-G光束通过大气湍流传输其光谱相干度会出现振荡和相位奇异现象，但随着湍流的增强，振荡减弱，直至振荡和相位奇异现象消失，这一特性与高斯-谢尔模型光束的差异很大.光束的相干参数越小，光束空间相干性受湍流的影响也越小.此外，还研究了光谱相干度二阶矩宽度与光谱强度二阶矩宽度间的关系，得到一些有意义的结果，并给出了合理的 关键词： 部分相干厄米-高斯光束 大气湍流 光谱相干度 二阶矩宽度

The influence of atmospheric turbulence on the spatial correlation property of partially coherent Hermite-Gaussian beams

Based on the extended Huygens-Fresnel principle, the expression for the spectral degree of coherence of the partially coherent Hermite-Gaussian (H-G) beams propagating through atmospheric turbulence is derived by using the quadratic approximation of Rytov's phase structure function, and the influence of atmospheric turbulence on the spatial correlation is studied. It is shown that the oscillatory behavior and phase singularities of the degree of spectral coherence may appear when partially coherent H-G beams propagate through atmospheric turbulence, which is very different from the behavior of Gaussian-Schell-model beams. But, the oscillatory behavior becomes weaker with increasing turbulence, and even disappears when the turbulence is strong enough. The smaller the coherence parameter, the less the spatial correlation property of partially coherent H-G beams is affected by the turbulence. In addition, a comparison between the mean-squared width of the spectral degree of coherence and the mean-squared width of the spectral intensity is also given. Some interesting results are obtained, and are explained with regard to their physical nature.