To improve the optical performance of the large-aperture optical antenna, the Cassegrain splicing receiving antenna consisting of spherical sub-mirrors with different curvatures is designed and optimized based on the three-dimensional (3-D) vector theory of rotation and reflection. Compared with the splicing antenna consisting of spherical sub-mirrors with the same curvatures, the antenna proposed in this paper can decrease the root mean square (RMS) of the spot radius at the receiving plane from 0.0202223 m to 0.0109724 m, and the spot size decreases 45.74%. Besides, the influence of on-axial defocusing and incident ray tilt on the performance of the optical antenna is analyzed. This paper provides not only a new antenna with better performance but also a new idea for designing large-aperture splicing optical antennas.

为提高大口径光学天线的光学性能，基于旋转和反射的三维（3-D）矢量理论，设计并优化了由不同曲率球面副镜组成的卡塞格林拼接接收天线。与由相同曲率球面副镜组成的拼接天线相比，本文提出的天线可以将接收平面光斑半径的均方根（RMS）从0.0202223 m减小到0.0109724 m，光斑尺寸下降 45.74%。此外，分析了同轴散焦和入射光线倾斜对光学天线性能的影响。本文不仅提供了一种性能更好的新型天线，而且为设计大口径拼接光学天线提供了新思路。