高斯-谢尔模光束在湍流大气中的传输特征参数

The Propagation Characteristic Parameters for the Gaussian Schell-Model Beam in a Turbulent Atmosphere

基于广义惠更斯-菲涅耳原理和Winger分布函数(WDF)二阶矩的定义,推导出高斯-谢尔模型(GSM)光束在湍流中的均方根束宽、角宽以及M2因子的解析表达式,并进行了详细分析和数值计算.结果表明,它们分别随光束的相干长度σ、束腰宽度w0、波长λ、湍流的折射率起伏结构常数C2n和传输距离z的变化而变化.随着C2n和z的增大,以及σ的减小,GSM光束在湍流大气中的均方根束宽、角宽以及M2因子明显增大.

Based on the generalized Huygens-Fresnel principle and the definition of the second-order moments of the Wigner distribution function（WDF）,the analytical formulas for the root-mean-square（rms） spatial and angular width and M2-factor of the Gaussian Schell-model（GSM）beam in turbulence have been derived.The results show that the M2-factor of the GSM beams propagating through the atmospheric turbulence depends mainly on degree of global coherence of the source,the waist size and the wavelength of the beams,the structure constant of the refractive-index fluctuations of the turbulence and the propagation distance.The rms spatial and angular width and M2-factor of the GSM beams in the turbulent atmosphere increase obviously with increasing the structure constant of the refractive-index fluctuations of the turbulence and the propagation distance.For the GSM beam with smaller spacial coherent length,the effect of turbulence on the change of the M2-factor is less.