红外相机CASCAM光学设计

介绍紫金山天文台研制的光学-近红外相机CASCAM（Chinese Academy of Science，CAMera)的光学系统设计．CASCAM相机以红外列阵HAWAII-1和光学CCD为探测器，配备国家天文台兴隆观测站2．16米和1．26米望远镜进行0．4—2．5μm波长范围的成像和偏振成像观测．相机的光学系统由F／9→F／6缩焦系统和Offner反射成像系统构成．优化设计结果表明，光学设计方案已满足天文观测的要求．CASCAM相机在设计上实现了光学-近红外很宽波段的消色差变焦，并在楔形分柬片、常温滤光片轮和折射式焦面摆动技术等方面进行了新的尝试．

Optical Design of Infrared Camera CASCAM

The optical design is introduced for the optical-infrared camera, CASCAM, developed by Purple Mountain Observatory.CASCAM employs an infrared array HAWAII-1 and a CCD, simultaneously covering the wavelengths of 0.4-2.5um, and is designed to make imaging and polarimetric imaging with the 2.16m and 1.26m telescopes at Xinglong station. The camera optics consists of a focal reducer and the Offner reflection system; the results of optimization with ZEMAX software show that the design can satisfy the proposed observational requirement. The camera design is implemented by the achromatic focal reducer well-designed for very wide wavelength band from optical to the near-infrared, and make some new attempts with wedged dichroic beam splitter non-refrigerated optical-filter wheels and refraction dithering system.