离轴发射望远镜发射调焦技术研究

Research on focusing of an off-axis laser launch telescope

为了实现离轴发射望远镜次镜调焦的目的,采用了六轴运动学姿态调焦和直线位置调焦的方式,对比直线位置调焦、角度调焦和位置调焦+角度补偿的方式,直线位置调焦在近距离时传递函数和波前比较好,角度调焦在中、远距离的时候调焦比较好,近距离较差,位置调焦+角度补偿则兼顾了两者的优点。使用光学设计软件设计了800mm口径的离轴发射望远镜,分别对10km、9km、8km、7km、5km、3km、1km、0.6km调焦发射像质评价,结果表明采用直线位置调焦+角度补偿的复合调焦方式获得的成像质量最好。

Focusing of an off-axis telescope with the secondary mirror is studied based on a hexapod positioning system and a linear stage. That have compared linear positional focusing, rotating focusing and a combination of them(the hybrid method), and concluded that the linear positional focusing achieves higher MTF and lower OPD at short focusing distances, the rotating focusing performs well at medium and large focusing distances, while the hybrid method could be applied at all distances. A 800 mm-diameter off-axis telescope is designed using the above methods, and the optical qualities at distances ranging from 0.6 km to 10 km are evaluated. Results show that the hybrid method leads to the highest imaging qualities.