灵巧型离轴三反光学系统设计

Compact and multispectral off-axial three-mirror reflective optical system

基于同轴三反射光学系统基本原理,将孔径光阑和视场适当偏心,设计了一个灵巧型多光谱离轴三反光学系统,系统焦距1 200mm,并对设计结果进行了像质评价。实验结果表明:系统在可见波段(0.486μm^0.656μm)80lp/mm空间频率下MTF>0.5,中波波段(3μm^5μm)15lp/mm空间频率下MTF>0.35,全波段范围内最大RMS为2.096μm。系统中面型采用二次非球面,且整个系统仅有孔径光阑偏心,3个反射镜位置均无偏心和倾斜,降低了加工成本及装调难度。

Based on the theory of coaxial three-mirror reflective optical system and by decenter-ing the aperture stop and the field of view ,a compact and multispectral off-axial three-mirror reflective optical system with 1 200 mm focal length was designed .Furthermore ,the image quality was evaluated .The design results prove that the modulation transfer function(MTF) is above 0 .5 at 80 lp/mm for 0 .486 μm ~0 .656 μm ,above 0 .35 at 17 lp/mm for 3 μm ~5 μm and the root-mean-square (RMS) radius is less than 2 .096 μm in full waveband .Moreover , three mirrors w hich use cone surfaces instead of high order aspherical surfaces are not decen-tered or tilted and only the aperture stop is decentered ,so it is easy to fabricate and assemble .