Adaptive optics system for Cassegrain focus of Subaru 8.2-m telescope
Adaptive optics system for Cassegrain focus of Subaru 8.2-m telescope
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Subaru 8.2米望远镜卡塞格伦焦点自适应光学系统
DOI：
10.1117/12.321685
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
M. Iye
中科院分区：
文献类型：
--
作者：
H. Takami;N. Takato;M. Otsubo;T. Kanzawa;Y. Kamata;Koji Nakashima;M. Iye
日本国家天文台 Subaru 8.2m 望远镜的自适应光学系统是为卡塞格伦耳红外仪器、CIAO 和 IRCS 开发的。该系统由具有 36 个子孔径光子计数雪崩光电二极管模块的波前曲率传感器和具有 36 个电极的双压电晶片变形镜组成。对于位于莫纳克亚山的中位视度为 0.45 角秒、R 等于 16 星等的明亮导星足够近的天体，K 波段的预期斯特列尔比超过 0.4。该系统将于1999年作为自然导星系统投入运行，最终将升级为激光导星系统，配合红外波前倾斜传感器提供近乎完整的天空。我们位于东京的实验室目前正在为斯巴鲁望远镜建造这种通用系统。在开始制造这个通用系统之前，我们在东京天文台构建了一个全尺寸原型系统并使用 1.6 m 红外望远镜进行了测试。该系统具有与 Subaru 系统相同的光学设计、可变形镜、环路控制计算机，而波前传感探测器是灵敏度较低的模拟 APD。我们成功地获得了具有衍射限制核心的 K 波段恒星的闭环图像。观测期间平均视宁度为2角秒的情况下，K波段的斯特列尔比约为0.5，改善系数约为20。系统的循环速度为每秒 2 K 校正。
The adaptive optics system for Subaru 8.2m telescope of the National Astronomical Observatory Japan has been developed for the Cassegrain ear-IR instruments, CIAO and IRCS. The system consists of a wavefront curvature sensor with 36 subaperture photon-counting avalanche photodiode modules and a bimorph deformable mirror with 36 electrodes. The expected Strehl ratio at K band exceeds 0.4 for objects that are located close enough to a bright guide star as faint as R equals 16 mag at the median seeing of 0.45 arcsec at Mauna Kea. The system will be in operation in 1999 as a natural guide star system, and will eventually be upgraded to a laser guide star system in cooperating an IR wavefront tilt sensor to provide nearly full sky. The construction of this common use system to Subaru telescope is now underway in our laboratory in Tokyo. Prior to starting the fabrication of this common use system, a full size prototype system was constructed and tested with the 1.6 m IR telescope at our observatory in Tokyo. This system has the identical optical design, deformable mirror, loop control computer to those for the Subaru system, while the wavefront sensing detectors were less-sensitive analog APDs. We succeeded in getting closed loop images of stars in K band with diffraction limited core. The Strehl ratio was around 0.5 and the factor of improvement was about 20 at K-band under the average seeing of 2 arcsec during the observation. The loop sped of the system was 2 K corrections per second.