基于Offner结构分视场成像光谱仪光学设计

为满足航天应用中仪器小型和轻量化、大视场的观测要求，通过分析现有Offner成像光谱仪，给出了一种简单的采用凸面光栅设计成像光谱仪的方法。并据此方法设计了一应用于400 km高度，波段范围为0.4~1 μm，焦距为720 mm，F数为5，全视场大小为4.3°的分视场成像光谱仪系统。分视场采用光纤将望远系统的细长像面连接到光谱仪的三个不同狭缝而实现。三狭缝光谱面共用一个像元数为1 024×1 024，像元大小18 μm×18 μm的CCD探测器。通过ZEMAX软件优化和公差分析后，系统在28 lp·mm-1处MTF优于0.62，光谱分辨率优于5 nm，地面分辨率小于10 m，能很好的满足大视场应用要求，该光学系统刈幅宽度相当于国内已研制成功的同类最好仪器的三倍。

Sub-Field Imaging Spectrometer Design Based on Offner Structure

To satisfy imaging spectrometers’s miniaturization, lightweight and large field requirements in space application, the current optical design of imaging spectrometer with Offner structure was analyzed, and an simple method to design imaging spectrometer with concave grating based on current ways was given. Using the method offered, the sub-field imaging spectrometer with 400 km altitude, 0.4~1.0 μm wavelength range, 5 F-number of 720 mm focal length and 4.3°total field was designed. Optical fiber was used to transfer the image in telescope’s focal plane to three slits arranged in the same plane so as to achieve sub-field. The CCD detector with 1 024×1 024 and 18 μm×18 μm was used to receive the image of the three slits after dispersing. Using ZEMAX software optimization and tolerance analysis, the system can satisfy 5 nm spectrum resolution and 5 m field resolution, and the MTF is over 0.62 with 28 lp·mm-1. The field of the system is almost 3 times that of similar instruments used in space probe.