大视场可见红外一体化光学系统设计

Design of large field for visible/infrared integrated optical system

使用光学设计软件设计了一种大视场可见红外一体化反射式光学系统,可见光和红外视场的大小分别为5.2°和5.12°。在光学系统的轨道高度为675 km的情况下,可对地面目标进行61.3 km和60.36 km的大幅宽观测。在光学系统采用偏视场设计将可见光和红外光的视场进行分离,可以实现双光路、双波段、双视场同时成像观测,避免了使用分光装置对光能量吸收造成损失,提高了光能利用率。可见光系统选用一个焦距为9 000 mm的三反系统,红外光学系统选用两个三反系统,后置三反系统的入瞳与前置三反系统的出瞳位置重合,系统总焦距为2 025 mm。经过优化,可见光系统的MTF在50 lp/mm达到0.45以上,红外系统的MTF在25 lp/mm达到0.65以上,成像质量均达到衍射极限。

A visible infrared integrated optical system of a large field of view is designed by using optical software, and the FOVs of the visible system and infrared system are 5.2 degrees and 5.12 degrees respectively. The orbit of the system is 675 kilometers, and have a large width of 61.3 kilometers and 60.36 kilometers respectively can be observed. The system uses a partial field to separate the field of visible light and infrared light respectively, and realize dual optical paths, dual bands and double fields of view imaging at the same time, which improve utility of visible light and infrared light by avoid the use of dividing light elements. Visible light system selects a three mirror system with a focal length of 9 000 mm. The infrared system uses two three mirror systems with a total focal length of 2 025 mm, and the entrance pupil of the rear system has the same position and size with the exit pupil of the former system. After optimizing, the modulation transfer function of the visible system is more than 0.45 at 50 lp/mm, and the infrared system＇s modulation transfer function is above 0.65 at 25 lp/mm respectively. The imaging quality of both systems reaches the diffraction limit.