对偏视场光学系统的遮光罩进行优化设计。偏视场在一个方向上非对称, 设计主镜内遮光罩需要进行光线追迹, 难度大。采用痕迹图方法获得光线在空间的位置坐标, 确定系统有效视场大小及挡光部分位置, 对内遮光罩的挡光部分进行开口处理, 得到一个上短下长的特殊“鸭嘴型”遮光罩, 降低设计难度。经过优化分析, 最终的主镜内遮光罩沿Z轴方向的尺寸缩减为原来的一半, 在Y轴方向上尺寸减小来降低非有效视场的大小。使用TracePro软件对设计好的遮光罩进行建模、仿真, 得到PST在离轴角度为30°时达到10-9量级, 小于系统的5.59×10-7指标要求。结果表明: 使用痕迹图法对偏视场光学系统的主镜内遮光罩进行设计是可行的。

A partial field optical system baffle was designed and optimized. Partial field was non-symmetry along one direction, so a large number light tracing was needed to design the centric, which made it difficult to design. A method of footprint diagram was used to get the coordinate of special light in the space, the size of effective field and the part of baffle blocking light. The part blocking light was removed and a "duck mouth shaped" baffle was got, which can decrease the difficulty of design. By optimizing the design, length of final designed baffle was half of the former one, and reduced the size along Y direction, which can reduce more stray light to enter the later optical system directly. Baffle was modeled and simulated by Solidworks and TracePro software, the PST is about 10-9 when the off-axis angle is 30°, which is less than 5.59×10-7, the requirement of the system. The result of the simulation shows that using method of footprint diagram to design inner baffle of a partial field optical system is feasible.