一种含自由曲面的离轴三反光学系统设计

The design of an off-axis three-mirror optical system with a freeform surface

设计了一种含自由曲面的离轴三反射镜红外光学系统,光学系统采用三个离轴反射镜,其中第二反射镜采用自由曲面面型,其余反射镜采用非球面面型。光学系统接收口径Φ100 mm,F/#2.5。由于反射元件不产生色差,因此光学系统不存在色差。同时反射元件与支撑结构件采用同一材料,光学系统实现无热化设计。利用自由曲面的非旋转对称性,系统轴外像差得到了很好的校正,从而使光学系统成像质量接近衍射极限。通过合理布局三个反射镜的位置,使光学系统外形尺寸达到了160 mm×110 mm×250 mm。

In this paper,an off-axis three-mirror optical system is designed using freeform surface.There are three off-axis mirrors in the optical system,the second mirror adopts freeform surface,and the rest are with asphere surface.The aperture of the optical system isΦ100 mm,and the F/#is 2.5.The system is free of chromatic aberration because of using the reflecting optics.For the optics and mount are made of the same material,the optical system is athermalization.The system off-axis aberrations are well corrected by using the non-rotational symmetry of free-form surface.Thus the optical system is diffraction-limited.By properly layout of the three off-axis mirrors,the dimension of the optical system reaches 160 mm×110 mm×250 mm.