空间成像与激光通信共口径光学系统设计

Design of co-aperture optical system for space imaging and laser communication

针对空间成像系统与激光通信天线同时需要大口径光学系统而使卫星载荷质量增大的问题,提出了一种成像光学系统与收发合一激光通信天线共口径工作的新型光学系统。从像差理论出发,给出了以主次反射镜为共用部分、成像和通信工作在不同视场的共口径光学系统初始结构设计方法。实际设计了共口径光学系统,该系统口径为600mm,次镜遮拦比为0.225,成像系统的传递函数在50lp/mm时大于0.47,接近衍射极限;发射分系统波像差远小于λ/20,发射激光的最小束散角可达4μrad,出射光斑质量良好;接收系统达到衍射极限,光斑远小于探测端面,满足探测要求。最后,进行了公差分析,给出了光学系统的装调方法。该设计通过共用主次镜减少了系统总质量和总体积,同时满足空间成像和激光通信系统的性能要求。

Both space optical system and laser communicating antenna need a large aperture optical system,which increases the load of a satellite.This paper proposes a new co-aperture optical system for space imaging and laser communication to decrease the mass of the satellite.On the basis of primary aberration theory,the design method of initial configuration of the co-aperture optical system was presented,in which the imaging and communication share primary and secondary mirrors and work at different fields.A co-aperture optical system was designed with a primary mirror with a diameter of 600 mm and a secondary mirror with a obstruction ratio of 0.225.The system shows good imaging capability and its Modulation Transfer Function（MTF） for all field of view is more than 0.47,very close to the diffraction limitation.The RMS wavefront of the laser sending section is far less than λ/20,and the sending laser beam is in good quality with a least divergence angle about 4 μrad.The size of the light spot on the imaging surface is less than that of detecting surface,which satisfies the detecting request.Finally,the tolerance analysis was preformed and the assembling method was given.By sharing the primary and secondary mirrors,this design reduces the mass and volume of the system and satisfies the needs of space imaging and laser communication.