光学学报, 2014, 34 (12): 1222005, 网络出版: 2014-11-07
无遮拦三反射镜变形光学系统设计
Design of Unobscured Three-Mirror Anamorphic Optical Systems
摘要
变形光学系统在X方向和Y方向有不同的焦距,物方视场的横纵比不再受探测器光接收面形状限制,可以在一个方向上扩大视场或提高目标分辨率而不影响另外一个方向。研究了无遮拦三反射镜变形光学系统的设计方法,利用Zernike像差分析方法分析变形系统的像差特点,使用具有双曲率的Biconic Zernike曲面作为反射面校正系统像差。设计了一个X方向焦距fx为100 mm,Y方向焦距fy为150 mm,F数为2,视场为3.3°×1.65°的致冷型中波红外光学系统。探测器的横纵比为43,物方视场横纵比为21。该系统全视场范围内的调制传递函数在奈奎斯特频率处(33 lp/mm)高于0.61。三个反射面及整个光学系统均关于YZ平面对称。设计结果表明,该系统能够改变物方视场的横纵比,增大了X方向的视场,结构紧凑,成像质量良好。
Abstract
Anamorphic optical systems have different focal lengths in X and Y direction, objective field of view (FOV) aspect ratio will not be restrained by detector aspect ratio, so it can enlarge the FOV or improve the target resolution in one direction while not affecting another direction. Design method of unobscured three mirror anamorphic optical systems is studied. Zernike aberration analytical method is used to analyze the aberration characteristics. Biconic Zernike surfaces of double curvature is used to correct the aberrations. A cooled mid-wave infrared optical system is designed at focal length in X direction of fx=100 mm, focal length in Y direction of fy=150 mm, F number of 2 with FOV of 3.3°×1.65°. The aspect ratio of the detector is 43 and the aspect ratio of the objective FOV is 21. The modulation transfer function of this system is above 0.61 all over the FOV at the Nyquist frequency of 33 lp/mm. Each reflective surface and the whole system are symmetric about the YZ plane. The result shows that this system can change the aspect ratio in objective FOV and enlarge the FOV in X direction with compact structure and favorable image quality.
朱浩, 崔庆丰, 朴明旭. 无遮拦三反射镜变形光学系统设计[J]. 光学学报, 2014, 34(12): 1222005. Zhu Hao, Cui Qingfeng, Piao Mingxu. Design of Unobscured Three-Mirror Anamorphic Optical Systems[J]. Acta Optica Sinica, 2014, 34(12): 1222005.