大视场离轴三反光学系统设计  

Optical Design of Off-axis Three-mirror System with Wide Field

作　　者：罗秦[1,2,3] 张冬冬[1] 钮新华[1] 

机构地区：[1]中国科学院上海技术物理研究所,上海200083 [2]中国科学院红外探测与成像技术重点实验室,上海200083 [3]中国科学院大学,北京100049

出　　处：《红外》2017年第8期14-18,47,共6页Infrared

摘　　要：针对地球环境遥感的大视场和宽光谱的应用需求,在同轴三反光学系统的基础上,通过视场离轴实现了无中心遮拦,并设计了一种焦距为120 mm、F数为3.5、工作波长为0.4~1.65μm、像元尺寸为7.5μm以及采用Cook三片式结构的光学系统。在没有使用自由曲面的情况下,实现了30°×4°的大视场。其中,主镜为六次双曲面,次镜为二次扁椭圆面,三镜为四次扁椭圆面。在全视场范围内,该系统在奈奎斯特频率处的调制传递函数(Modulation Transfer Function,MTF)大于0.6,接近衍射极限。其弥散斑直径的均方根值小于探测器的像元尺寸,畸变小于2.5%,说明本文系统具有优良的成像性能。To meet the application needs of wide field and wide spectrum of earth environment remote sensing, a center without obstructing is realized by means of field off-axis on the basis of coaxial three- mirror optical systems. An optical system with a Cook three-mirror structure is designed. The optical system has its focal length of 120 mm, F number of 3.5, operating wavelength of 0.4 to 1.65μm and pixel size of 7.5 μm. it realizes the 30°×4° large field of view without any free-form surfaces. In the optical system, the primary mirror is a 6 times hyperboloid; the second mirror is a secondary flat ellipse and the third mirror is a 4 times flat ellipse. The system has its Modulation Transfer Function （MTF） greater than 0.6 at the Nyquist freaquency in the whole field of view, which is close to the diffraction limit. Its RMS dispersion spot diameter is less than the pixel size of the detector and its distortion is less than 2.5%. These results show that the system has excellent imaging performance.

关 键 词：光学设计 大视场 离轴三反光学系统 

分 类 号：X87[环境科学与工程—环境工程]