RGB三通道衍射望远镜光学成像系统设计

Design of optical imaging system for RGB three-channel diffraction telescope

基于目前研究较热的大口径衍射望远镜技术,提出一种在可见光范围内进行成像的衍射望远镜光学系统方案。该方案解决了目前衍射望远镜存在的成像频谱范围较窄的问题,可以在可见光范围内获取彩色图像,设计方法是将衍射元件沿径向分为3个通道,分别对R、G、B三个颜色通道进行成像,每个通道的成像带宽为40 nm,通过控制系统参数使3个通道的像在像面处重合,获取彩色图像。设计了基于25 m口径衍射主镜的三通道望远镜光学系统,并对该系统进行建模仿真,仿真结果与设计理论相符。该方案可以增加成像的频谱范围,其像面光斑具有与单通道系统像面光斑近乎相同的主瓣宽度。

Based on the large aperture diffraction telescope which is currently being studied, a scheme of optical system for diffraction telescope imaging in visible light range was proposed. The scheme solves the problem of narrow imaging spectrum existing in the current diffraction telescope and can obtain color images in the light range. The specific design methods are as follows: the diffraction elements are dividing into three channels along the radial direction, and the information of three color channels of R, G and B are imaged respectively,the imaging bandwidth of each channel is 40 nm;then by controlling the system parameters, the images of the three channels can coincide at the image plane and are acquired by the image sensor. A three-channel telescope optical system based on 25 m aperture diffraction primary mirror was designed and simulated. The simulation results agree with the design theory. The scheme can increase the spectral range of the system, and can get the same main lobe width as that of the single channel system.