湍流尺度对高斯谢尔光束闪烁孔径平滑的影响

通过运用包含湍流内、外尺度因子的调制折射谱和波场交叉谱密度函数的互相干函数近似,研究了大气湍流内、外尺度对高斯谢尔光束闪烁孔径平滑的影响,得出了弱大气湍流起伏环境下包含大气湍流外尺度因素的高斯谢尔光束闪烁孔径平滑因子。结果表明,随着湍流外尺度的减小,孔径对高斯谢尔光束的大气闪烁平滑作用减小,湍流外尺度对不相干光闪烁孔径平滑作用的影响可以忽略。

Effects of the turbulent scales on aperture averaging of a Gaussian-Schell beam propagation in a turbulent atmosphere

The effects of atmospheric scales on aperture averagin g of Gaussian-Schell beam propagating in an atmospheric turbulence were examine d by means of a modulation spectrum for the index of refraction fluctuations inc luding the outer-and-inner scales of the atmospheric turbulence and the approx imation of a cross-spectral density function for the coherent function.An easil y evaluated expression valid in the weak fluctuation regime for aperture-averag ing factor including the effects of the turbulent outer-scale was obtained.The results show that with the outer-scale reducing,the aperture averaging of scint illations for Gaussian-Schell beam propagating in an atmospheric turbulence wil l reduce.The effect of the outer-scale of turbulence on the aperture averaging of scintillations for incoherence beam can be ignored.