大口径主焦点式光学系统的设计与装调

Design and alignment of large-aperture prime focus optical system

为满足大口径主焦点光学望远镜的发展趋势与需求,研究了大口径主焦点式光学系统的设计与装调方法。给出一个大口径主焦点光学系统的设计,该系统由一块非球面主反射镜和六块口径较小的球面透镜组成,六块透镜构成的校正镜组能够增大视场、校正像差,从而保证系统的成像质量。该系统的工作波段为0.4~0.8μm,通光口径为1000 mm,焦距为1300 mm,视场为2.7°×2.7°,在-40~50℃内采用移动探测像面的方式实现温度补偿。全视场奈奎斯特频率下调制传递函数高于0.45,RMS弥散斑半径小于10μm。针对该系统,提出了一种包含主镜被动支撑调整、校正镜定心装调和系统星点成像装调的一般装调方法,装调后系统全视场靶面星点80%能量集中度在3×3个像元以内。

Considering the development trends and demands of large-aperture prime focus optical tele⁃scopes,design and alignment methods for a large-aperture prime focus optical system were analyzed.A prime focus optical system with a large aperture was presented.This system was composed of an aspheri⁃cal primary mirror and six spherical lenses with smaller apertures.The corrective lens could be used to en⁃large the field of view,correct image aberrations,and ensure the image quality of the system.This sys⁃tem has a focal length of 1300 mm,working waveband of 0.4-0.8μm,clear aperture of 1000 mm,and a 2.7°×2.7°field of view.In addition,this system was compensated by moving the detection image plane in the range of-40-+50℃.The modulation transfer function(MTF)of the system was above 0.45 at the Nyquist frequency,and the RMS speckle radius was less than 10μm in the full field of view.A general method including the adjustment of the primary mirror,corrective lens,and system was pro⁃posed for this system,the results of which indicated that the star point 80%energy concentration degree in the full field of view of the system was in a 3×3 pixels region of the target area.