光学系统中像散和离焦对信号光远场特性的影响

在自由空间光通信中,光学系统的像散与离焦是影响信号光远场特性的主要因素之一。由像差理论出发,根据卡塞格伦望远系统的特点,利用Zernike-Annular多项式来描述像散和离焦,理论分析和数值仿真像散和离焦对信号光的远场特性的影响。仿真结果表明：像散和离焦都将减弱卫星接收端接收天线的接收光功率;由于像散不具有旋转对称性,从而使得在接收平面上的强度分布也不再具备旋转对称性,所以,接收端光束的＂有效接收面积＂不再为圆形;离焦和像散都不改变理想高斯光束在接收平面上光束的中心位置。

Influence of Astigmatism and Curvature Aberrations on Far-field Behavior of Signal Beams

In Inter-satellite Optical Communication, because optical devices in orbit are affected by their en- vironment, the wave--front aberration of the beam from antenna which would influence the contribution of the intensity in receiving plane is caused. Among all of the aberration, astigmatism aberration and curva- ture aberration of the optical system in radiation terminal are the primary factor in influencing the signal optical far--field in inter--satellite optical communication. According to the aberration theory, the influ- ence of coma and sphere aberration on the wave-front of signal beams is described, and then the theoretic analysis and numerical simulation of signal optical far--field is done. The results indicate that both astig- matism aberration and curvature aberration would reduce the power in the receiver, and astigmatism＇s in- fluence is more than curvature＇s; because the density distribution of the Gaussian beam with astigmatism aberration is not rotational symmetry, the effectual receiving area of the satellite is not rotundity. The re- sults also indicate than both astigmatism aberration and curvature aberration would not change the center of the ideal Gaussian beam in the receiving plane.