A near-infrared tip-tilt sensor for the Keck I laser guide star adaptive optics system
A near-infrared tip-tilt sensor for the Keck I laser guide star adaptive optics system
复制标题
用于 Keck I 激光导星自适应光学系统的近红外倾斜传感器
DOI：
10.1117/12.2055279
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发表时间：
2014
影响因子：
2.1
通讯作者：
T. Stalcup
中科院分区：
文献类型：
--
作者：
P. Wizinowich;Roger M. Smith;R. Biasi;S. Cetre;R. Dekany;Bruno Femenía;J. Fucik;D. Hale;C. Neyman;D. Pescoller;S. Ragland;P. Stomski;M. Andrighettoni;R. Bartos;K. Bui;A. Cooper;J. Cromer;M. V. van Dam;M. Hess;E. James;J. Lyke;H. Rodriguez;T. Stalcup
激光导星 (LGS) 自适应光学 (AO) 系统的天空覆盖范围和性能受到用于低阶校正的自然导星 (NGS) 的限制。通过在近红外范围内测量 NGS 的尖端和倾斜，可以显着减少这种限制，其中 NGS 由 LGS AO 系统部分校正，并且恒星通常比可见波长亮几个数量级。我们展示了近红外倾斜传感器的设计，该传感器最近与 Keck I 望远镜的 LGS AO 系统集成，并提供了一些初步的天空结果。实施涉及对 AO 工作台、实时控制系统以及更高级别的控制和操作软件的修改，这些也将被讨论。倾斜传感器是基于 H2RG 的近红外相机，像素为 0.05 角秒。通过仅读取以 100 角秒直径场中任何位置的 NGS 为中心的 2×2 至 16×16 像素的小感兴趣区域，即可实现高采样率下的低噪声。该传感器使用位于 OSIRIS 积分场摄谱仪前面的二向色分光镜反射的光，在 Ks 或 H 波段工作。
The sky coverage and performance of laser guide star (LGS) adaptive optics (AO) systems is limited by the natural guide star (NGS) used for low order correction. This limitation can be dramatically reduced by measuring the tip and tilt of the NGS in the near-infrared where the NGS is partially corrected by the LGS AO system and where stars are generally several magnitudes brighter than at visible wavelengths. We present the design of a near-infrared tip-tilt sensor that has recently been integrated with the Keck I telescope’s LGS AO system along with some initial on-sky results. The implementation involved modifications to the AO bench, real-time control system, and higher level controls and operations software that will also be discussed. The tip-tilt sensor is a H2RG-based near-infrared camera with 0.05 arc second pixels. Low noise at high sample rates is achieved by only reading a small region of interest, from 2×2 to 16×16 pixels, centered on an NGS anywhere in the 100 arc second diameter field. The sensor operates at either Ks or H-band using light reflected by a choice of dichroic beamsplitters located in front of the OSIRIS integral field spectrograph.