湍流大气传输高斯谢尔光束的到达角起伏

Angle-of-arrival of Gaussian Schell Beam Propagation in Atmospheric Turbulence

研究了在弱大气湍流起伏环境下以窄带宽高斯谢尔光束为激光光源的大气通信问题,分析了大气湍流强度和光源空间相干度对通信光束到达角起伏的影响采用窄带宽光场的交叉谱密度函数代替光场互相干函数的近似方法和采用包含大气湍流内外尺度的简化折射率谱密度函数,得出了湍流大气中传输高斯谢尔光束的波结构函数(WSF)和到达角起伏方差解析近似关系分析表明。

An atmospheric optical communication link is considered, in which the laser source is a narrowband Gaussian Shell beam and the link is working in the weak fluctuation regime. The effects of atmospheric turbulence strength and degree of source spatial coherence on the angle-of-arrival are examined. To accomplish this, we have used the cross-spectral density function of the narrowband fields in place of the mutual coherence function and have used the power spectral density of the refractive-index fluctuations which include the factor of small-and large-scale sizes turbulence eddies. Expressions for the wave structure function and the variance of the angle-of-arrival of Gaussian Schell beam propagation in isotropic and homogeneous atmospheric turbulence are developed. The analysis indicates the turbulence spreading of the beam and the degree of source spatial coherence are two main factors which affect the wave structure function and the variance of the angle-of-arrival of the propagating beam.