Infrared Optics Design for the Japan National Large Telescope Project

日本国家天文台(NAOJ)正在夏威夷莫纳克亚山顶建造一个8米高的反射镜，该山顶被认为是最适合进行红外观测的地点。Nariai博士留在夏威夷，与夏威夷大学和莫纳克亚天文台的工作人员合作，评估现有望远镜和莫纳克亚星空的红外数据，并为日本国家大望远镜(JNLT)设计光学系统。设计工作产生了F/12.2和斩波式F/35红外镜系统，对于后者，引入了主镜的主动变形，以确保中红外(-0)直射图像的折射极限分辨率。2)使用快速发展的二维阵列探测器。还首次采用新的玻璃材料设计了用于主焦红外观测的广视场校正器。为了最大限度地减少仪器的热噪声背景，推荐了各种装置，但一些关键问题，如支撑第二和第三反射镜的结构的辐射消耗，仍有待后续任务的研究。

National Astronomical Observatory of Japan (NAOJ) is constructing an 8m reflector at the summit of Mauna Kea in Hawaii which is known to be most suitable site for infrared observation. Dr. Nariai stayed in Hawaii and collaborated with staff members of University of Hawaii and of Mauna Kea Observatories in evaluating infrared data of existing telescopes and Mauna Kea sky, and in designing optical systems for the Japan National Large Telescope (JNLT).The design work resulted in an F/12.2 and a chopping F/35 IR mirror system, for the latter of which active deformation of the main mirror was introduced in order to secure defraction-limit resolution of direct images in mid-IR (-0."2) using quickly developing 2-D array detectors.A wide-field corrector for IR observation at the primary focus was also designed by adopting new glass material for the first time.In order to minimize the instrumental thermal noise background, various devices were recommended, but some crucial issues, such as depletion of radiation from structures supporting the secondary and the tertiary mirrors, remained to be investigated in follow-on tasks.