捕获是激光通信建立的必要手段，为探索通信中光学系统各像差对捕获性能的影响，从信标光传输过程和激光通信像质评价方式出发，分析了单色像差均方根小于0.2λ时对捕获质心处光强的影响，采用质心和加权质心方法计算了彗差、倾斜(畸变)所造成的捕获偏差；同时分析了各种单色像差之间对质心光强、捕获偏差的补偿关系。分析表明离焦能对球差、像散造成的质心光强下降有较好的补偿作用，畸变产生的捕获偏差可以用彗差进行完全补偿。采用Zemax软件设计了卡塞格林式和离轴三反(TMA)通信天线系统，利用该方法计算了在视场小于0.3°、像差综合作用时捕获的质心光强和引入的捕获偏差。计算结果很好地验证了分析结论，这些结论对空间激光天线选型、像质优化策略具有一定的借鉴作用。

Acquisition is essential to laser communication link′s establishing. In order to study the impact of optical aberrations on acquisition performances, based on the transmission process of beacon beam and image quality evaluation of laser communication system, the impact of monochromatic aberrations on acquisition centroid intensity and acquisition errors caused by tilt and coma with centroid and weighted centroid algorithm is analyzed as the root mean square (RMS) of monochromatic aberrations is less than 0.2λ. Besides, compensations between aberrations to the centroid intensity and acquisition errors are also discussed. The analysis reveales that acquisition errors caused by tilt (distortion) and coma can completely compensate for each other, and defocus can greatly compensate the centroid intensity decrease caused by sphere and astigmatism. The Cassegrain and three-mirror anastignat (TMA) antenna systems are designed by Zemax optical software, and by using the method, the combined effect of aberration on centroid intensity and acquisition errors within 0.3° circle field is calculated. The result can sufficiently support the above view. These conclusions can give some guides to antenna type selection and image quality optimization strategy in laser communication optical system design.