光学学报, 2009, 29 (12): 3241, 网络出版: 2009-12-23
部分相干厄米-高斯列阵光束通过湍流大气传输的方向性
Directionality of Partially Coherent Hermite-Gaussian Array Beams Propagating in Atmospheric Turbulence
大气光学 方向性 湍流 部分相干厄米-高斯列阵光束 远场发散角 远场平均光强 atmospheric optics directionality turbulence partially coherent Hermite-Gaussian (H-G) array be far-field divergence angle far-field average intensity
摘要
推导出了部分相干厄米-高斯(H-G)列阵光束通过湍流大气传输的二阶矩束宽和远场发散角的解析公式。采用远场发散角作为光束方向性的评价参数,研究了部分相干H-G列阵光束通过湍流大气传输的方向性。研究表明:在一定条件下,部分相干H-G列阵光束与对应的高斯光束不论在自由空间还是湍流大气中均具有相同的方向性。此外,进一步研究发现,在自由空间中,由远场发散角和归一化远场平均光强分布所表征的部分相干H-G列阵光束的方向性是不一致的,但湍流可以使得两种描述相一致。这一结论与高斯-谢尔模型(GSM)列阵光束的相关结论存在差异。在自由空间中,与高斯光束具有相同远场发散角的非相干合成的GSM列阵光束与对应的高斯光束具有相同的归一化远场光强分布。
Abstract
The closed-form expressions for the mean-squared beam width and the far-field divergence angle of partially coherent Hermite-Gaussian (H-G) array beams propagating in atmospheric turbulence are derived. The far-field divergence angle is chosen as the characteristic parameter of beam directionality,and the directionality of partially coherent H-G array beams propagating in atmospheric turbulence is studied. It is shown that under certain conditions,partially coherent H-G array beams may generate the same directionality as a Gaussian laser beam in free space and also in turbulence. Furthermore,it is found that,the directionality of H-G array beams in terms of the far-field divergence angle is not consistent with that in terms of the normalized far-field average intensity distribution in free space,but both may be consistent in atmospheric turbulence. The result is some different from the behavior of GSM array beams. For the incoherent combination case,GSM array beams with the same far-field divergence angle as a Gaussian beam will have the same normalized far-field intensity distribution as the Gaussian beam in free space.
李晓庆, 季小玲. 部分相干厄米-高斯列阵光束通过湍流大气传输的方向性[J]. 光学学报, 2009, 29(12): 3241. Li Xiaoqing, Ji Xiaoling. Directionality of Partially Coherent Hermite-Gaussian Array Beams Propagating in Atmospheric Turbulence[J]. Acta Optica Sinica, 2009, 29(12): 3241.