Chu Xiuxiang, Qiao Chunhong, Feng Xiaoxing, Chen Ruipin
School of Sciences, Zhejiang Agriculture and Forestry University, Lin’an 311300, China.
Appl Opt. 2011 Jul 20;50(21):3871-8. doi: 10.1364/AO.50.003871.
We propose a method that is used to derive the moment radius of intensity distribution in a turbulent atmosphere. From this study, we have found that the second moment radius is affected only by the first-order expansion coefficient of the wave structure function. If our attention is directed to a higher moment radius, a higher order approximation of the expansion needs to be used. As an example, the propagation of a Gaussian-Schell beam in a slant path has been studied based on the turbulent atmosphere of a three-layer model. The variation of some beam properties, such as the relative waist width, angular spread, and kurtosis parameter with the initial waist width, wavelength, and zenith angle, has been analyzed and discussed in detail. The study shows that there is little difference between the three-layer model and the Kolmogorov model in studying uplink propagation, and the difference is large for downlink propagation. The intensity profile of the Gaussian beam in turbulence does not keep a Gaussian shape unless the beam spreading due to turbulence is very large or very small.
我们提出了一种用于推导湍流大气中强度分布的矩半径的方法。通过这项研究，我们发现二阶矩半径仅受波结构函数的一阶展开系数影响。如果我们关注更高阶的矩半径，则需要使用展开的更高阶近似。例如，基于三层模型的湍流大气研究了高斯 - 谢尔光束在倾斜路径中的传播。详细分析和讨论了一些光束特性的变化，如相对束腰宽度、角扩展和峰度参数随初始束腰宽度、波长和天顶角的变化。研究表明，在研究上行链路传播时，三层模型与柯尔莫哥洛夫模型之间差异不大，而在下行链路传播中差异较大。除非由于湍流引起的光束扩展非常大或非常小，否则湍流中高斯光束的强度分布不会保持高斯形状。
