红外折／衍混合离轴望远系统设计

DESIGN OF INFRARED HYBRID REFRACTIVE-DIFFRACTIVE OFF-AXIAL TELESCOPIC OPTICAL SYSTEM

本文针对空间光学系统轻型特点，设计了一个二元光学折／衍混合红外反射式望远系统。采用了离轴式格里高利（Ｇｒｅｇｏｒｉａｎ）结构形式，消除了望远系统中的中心遮拦问题。用衍射光学元件校正系统象差，使反射面为球面，二元光学表面尺寸比施密特（Ｓｃｈｍｉｄｔ）校正板（位于入瞳处）缩小于３～４倍，光学设计运用ＯＳＬＯ软件，光学系统的通光孔径φ＝１２０ｍｍ，焦距ｆ＝－１０００ｍｍ，波长λ＝４．３μｍ，视场２ω＝２°×６°（子午×弧矢），分辨率Ｒｅｓ＝０．０５ｍｍ，ＭＴＦ≥０．４（空间频率ｆｒｅ≤１０ｃ１／ｍｍ）。

A hybrid binary optical refractive-diffrative reflective telescopic optical system is designed by us for lighter optical system in aerospace.By adopting and off-axial refractive-diffractive-refiective Gregorian type,the center obstruction is banished. Aberrations of Optical system are corrected by using binary optical element.The reflective surfaces are spherical,binary optical surface size is reduced to the l/4～1/3 of the Schmidt system corrector.By using OSLO 4.2 SIX(Sinclair Optics Inc,)optical design software,an off-axial infrared telescope with a refrative-diffrative surface,whOse aperture φ120mm,effective focus length f=-1000mm,λ=4.3pm,field angle 2°×6°(tangential× sagittal directions),resolution.Res=0.05μm,modulation transfer function MTF≥0.4(if spatial frequency≤10cl/mm).