Ji Xiaoling, Chen Xiaowen, Lü Baida
Department of Physics, Sichuan Normal University, Chengdu 610068, China.
J Opt Soc Am A Opt Image Sci Vis. 2008 Jan;25(1):21-8. doi: 10.1364/josaa.25.000021.
The closed-form expression for the mean-squared beam width of partially coherent Hermite-Gaussian (H-G) beams propagating through atmospheric turbulence is derived. The influence of turbulence on the spreading of partially coherent H-G beams is studied quantitatively by examining the mean-squared beam width. It is found that the smaller the coherence length sigma(0) of the source is, and the larger the beam order m and the wavelength lambda are, the less partially coherent H-G beams are affected by the turbulence, although the beams with smaller sigma(0), larger m, and larger lambda have greater spreading in free space. In addition, it is shown that two partially coherent H-G beams may generate the same angular spread and that there exist equivalent partially coherent H-G beams that may have the same directionality as a fully coherent Gaussian beam in free space and also in turbulence. The results are illustrated by examples, and a comparison with previous work is also made.
推导了部分相干厄米-高斯（H-G）光束在大气湍流中传输时均方束宽的闭式表达式。通过研究均方束宽，定量地研究了湍流对部分相干H-G光束扩展的影响。研究发现，源的相干长度σ(0)越小，光束阶数m和波长λ越大，部分相干H-G光束受湍流的影响就越小，尽管σ(0)较小、m较大和λ较大的光束在自由空间中的扩展更大。此外，研究表明，两束部分相干H-G光束可能产生相同的角扩展，并且存在等效的部分相干H-G光束，它们在自由空间和湍流中都可能具有与完全相干高斯光束相同的方向性。文中通过实例对结果进行了说明，并与先前的工作进行了比较。
