Ding Chaoliang, Koivurova Matias, Turunen Jari, Pan Liuzhan
J Opt Soc Am A Opt Image Sci Vis. 2017 Aug 1;34(8):1441-1447. doi: 10.1364/JOSAA.34.001441.
In a recent publication [Opt. Lett.42, 1512 (2017)OPLEDP0146-959210.1364/OL.42.001512], a novel class of partially coherent sources with circular coherence was introduced. In this paper, we examine the propagation behavior of the spectral density and the spectral degree of spatial coherence of a beam generated by such a source in free space and in oceanic turbulent media. It is found that the beam exhibits self-focusing, which is dependent on the initial coherence and the parameters of oceanic turbulence. The self-focusing phenomenon disappears when the initial coherence is high enough or the oceanic turbulence is strong. The area of high coherence appears in the center and along two diagonal lines. With increasing turbulence, the coherence area reduces gradually along one diagonal line and is retained along the other one. A physical interpretation of the self-focusing phenomenon is presented, and potential applications in optical underwater communication and beam shaping are considered.
在最近的一篇出版物[《光学快报》42, 1512 (2017)，OPLEDP0146 - 959210.1364/OL.42.001512]中，引入了一类具有圆形相干性的新型部分相干源。在本文中，我们研究了由这种源产生的光束在自由空间和海洋湍流介质中的光谱密度和空间相干光谱度的传播行为。发现该光束呈现出自聚焦现象，这取决于初始相干性和海洋湍流的参数。当初始相干性足够高或海洋湍流很强时，自聚焦现象消失。高相干区域出现在中心和沿两条对角线处。随着湍流增加，相干区域沿一条对角线逐渐减小，而沿另一条对角线保持不变。给出了自聚焦现象的物理解释，并考虑了其在水下光通信和光束整形中的潜在应用。
