二维大视场紧凑型离轴四反光学系统设计  

Design of Compact Off-axis Four-mirror Optical System with Two-dimensional Large Field of View

作　　者：刘璐 胡斌[1] 周峰[1] 王钰 LIU Lu;HU Bin;ZHOU Feng;WANG Yu(Beijing Institute of Space Mechanics&Electricity,Beijing 100094,China)

机构地区：[1]北京空间机电研究所,北京100094

出　　处：《航天返回与遥感》2020年第1期73-84,共12页Spacecraft Recovery & Remote Sensing

摘　　要：针对空间红外遥感领域轻量化、系统时间分辨率高的需求,设计了一款二维大视场紧凑型离轴四反光学系统,该系统工作谱段为2.70~7.50μm,系统焦距为500mm,F数为3.5,视场角为18°×10°。光学系统设计采用了新型折叠光路型式,得到了灵巧紧凑的系统结构;利用XY多项式自由曲面面型描述方法对光学系统的各个镜面进行拟合,并结合标准Zernike多项式进行像差分析,将系统的四面反射镜设计为“凸-凸-凹-凹”的组合,拓宽了成像视场,实现了子午弧矢双方向大视场清晰成像。设计结果表明,全视场80%的能量集中在弥散斑直径20μm的圆内;公差分析后,在奈奎斯特频率(25线对/mm)处全视场调制传递函数优于0.57。该系统视场大、能量集中度高、结构紧凑,可为空间遥感宽谱段、凝视成像光学设计提供一定的参考。In order to meet the needs of lightweight and high temporal resolution in space remote sensing,a two-dimensional off-axis four-mirror optical system is designed with large field of view and compact configuration.The system works in the range of 2.70~7.50μm;the focal length of the system is 500mm;the F number is 3.5 and the field is 18°×10°.In the process of system design,a new type of folded optical path is adopted,and then a smart and compact system structure is obtained.By using the optical design method of XY polynomial free-form surface,combined with the aberration analysis method of standard Zernike polynomial,the four-sided mirror in the system is designed as a combination of convex–convex-concave-concave surfaces,which widens the imaging field of view and realizes clear imaging of meridian arc vector in two directions and large field of view.The design results show that 80%of the energy in the full field of view is concentrated in the circle with the RMS spot diameter of 20μm;after tolerance analysis,the MTF at Nyquist frequency is better than 0.57 at 25lp/mm.The system has large field of view,high energy concentration and compact configuration,providing a reference in optical design for space remote sensing in space wide spectrum and staring imaging.

关 键 词：大视场 离轴四反光路系统 自由曲面 XY 多项式 空间遥感 

分 类 号：O439[机械工程—光学工程]