王姣, 柯熙政. 部分相干光束在大气湍流中传输的散斑特性[J]. 红外与激光工程, 2017, 46(7): 722003-0722003(8). DOI: 10.3788/IRLA201746.0722003
引用本文: 王姣, 柯熙政. 部分相干光束在大气湍流中传输的散斑特性[J]. 红外与激光工程, 2017, 46(7): 722003-0722003(8). DOI: 10.3788/IRLA201746.0722003
Wang Jiao, Ke Xizheng. Speckle characteristics of partially coherent beam propagating in atmospheric turbulence[J]. Infrared and Laser Engineering, 2017, 46(7): 722003-0722003(8). DOI: 10.3788/IRLA201746.0722003
Citation: Wang Jiao, Ke Xizheng. Speckle characteristics of partially coherent beam propagating in atmospheric turbulence[J]. Infrared and Laser Engineering, 2017, 46(7): 722003-0722003(8). DOI: 10.3788/IRLA201746.0722003

部分相干光束在大气湍流中传输的散斑特性

Speckle characteristics of partially coherent beam propagating in atmospheric turbulence

  • 摘要: 光束在大气湍流中传输时,大气湍流效应对光束进行强度和相位的随机调制,最终在远场处形成散斑。以部分相干高斯-谢尔模型(Gaussian-Schell Model,GSM)光束为研究对象,根据广义的Huygens-Fresnel原理、修正Von Karman谱模型,推导了GSM光束在大气湍流中传输时接收端光束的有效半径和平均散斑半径的表达式。利用数值计算对比分析光源相关参数和大气湍流对光束有效半径和平均散斑半径的影响。研究表明:光束的初始束腰半径越大、相干长度越小以及波长越小时,接收端光束的有效半径和平均散斑半径受湍流的影响越小;大气折射率结构常数越大,光束扩展越严重,此时平均散斑半径越小;光束有效半径和平均散斑半径随湍流外尺度增大几乎无变化,随湍流内尺度的增大而减小。所得出的结论对无线激光通信系统中光束的捕获、对准与跟踪(Acquisition,Pointing and Tracking,APT)系统的设计提供一个重要的参考价值。

     

    Abstract: The intensity and phase of the beam propagated in the atmospheric turbulence were modulated by the effects of atmospheric turbulence, and then the speckle was formed in the far field. The partially coherent Gaussian-Schell Model (GSM) beam was taken as the research object. According to the generalized Huygens-Fresnel principle and the mode of the modified Von Karman spectrum, the expressions of the effective radius and the mean speckle radius of receiver beam were derived. The expressions were used to analyze the effects of the beam source parameters and atmospheric turbulence on the effective radius and the mean speckle radius. The numerical results show that the greater the waist radius of the beam source, the smaller the coherent length is, the smaller the wavelength is, and then the smaller the effects of atmospheric turbulence on the effective radius and the mean speckle radius of receiver beam are. The smaller refractive-index structure constant, the greater the beam spread and the smaller the mean speckle radius is. The effective radius and the mean speckle radius of receiver beam decrease with increasing inner-scale of turbulence, but have nearly no change with increasing outer-scale of turbulence. An important reference value will be provided for the design of the Acquisition, Tracking and Pointing (ATP) in atmospheric laser communication system.

     

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