部分空间相干光束在非Kolmogorov湍流大气中的有效曲率半径

激光在湍流大气中的传输有重要的理论研究和实际应用意义.以高斯-谢尔模型(GSM)光束作为部分空间相干光的典型例,基于非Kolmogorov谱和广义惠更斯-菲涅耳原理, 推导出GSM光束在非Kolmogorov湍流中的有效曲率半径的解析表达式. 重点研究了湍流参数(包括广义指数α,内尺度l₀,和外尺度L₀) 和传输距离z分别对GSM光束有效曲率半径的影响.结果表明, 有效曲率半径R_x(z)随α和z增加先减小然后再增大, 随L₀的减小而增大(3.6<α< 4),随l₀的增加而增大.并对结果做了物理解释.

Effective radius of curvature of spatially partially coherent beams propagating through non-Kolmogorov turbulence

The laser beam propagation through atmospheric turbulence is of importance for both theoretical study and practical applications. Taking the Gaussian Schell-model（GSM） beam as a typical example of spatially partially coherent beams,based on the non-Kolmogorov spectrum and generalized Huygens-Fresnel principle,the analytical expression for the effective radius of curvature of GSM beams propagating through non-Kolmogorov turbulence is derived.The effects of turbulence parameters（including generalized exponent parameter a,inner scale lo,and outer scale Lo） and propagation distance 2 on the effective radius of curvature of GSM beams are stressed.It is shown that the effective radius of curvature of GSM beams increases with outer scale L₀ decreasing for 3.6 <α< 4 and the inner scale l₀ increasing,but dose not monotonically vary with the increases of exponent parameterαand propagation distance z.The results are explained physically.