湍流大气中激光束经卡塞格伦天线后的传输

将卡塞格伦天线系统等效为一个环形光阑和括束器的组合,通过将环形光阑展开为复高斯函数的叠加,并利用广义的惠更斯-菲涅尔积分公式得到了准直的光束经卡塞格伦天线系统后衍射场的强度解析表达式。研究了湍流大气中光束经卡塞格伦天线衍射的传输特性及光强分布随折射率结构常数和天线遮挡比的影响。该研究工作将对大气激光通信中的端机性能的评估具有一定的意义。

Propagation of laser beams in the turbulent atmosphere passing through Cassegrain antenna

The Cassegrain telescope is treated as the combination of a beam expander and an annular aperture.Furthermore,by introducing a hard aperture function into a finite sum of complex Gaussian and based on the extended Huygens-Fresnel principle functions,the approximate analytical expression for the intensity distribution of a Gaussian beam passing through Cassegrain antenna in the turbulent atmosphere is derived.The intensity distribution of the diffracted Gaussian beam in the turbulent atmosphere versus the different values of diameter ratio and the different values of the position parameter are also studied and illustrated with numerical calculations.The results of this work have potential applications in study of the far field distribution measurement of the terminals of atmospheric laser communication.