GRAVITY Coudé Infrared Adaptive Optics (CIAO) system for the VLT Interferometer
GRAVITY Coudé Infrared Adaptive Optics (CIAO) system for the VLT Interferometer
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用于 VLT 干涉仪的 GRAVITY Coudé 红外自适应光学 (CIAO) 系统
DOI：
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发表时间：
2012
期刊：
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通讯作者：
M. Suárez Valles
中科院分区：
文献类型：
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作者：
S. Kendrew;S. Hippler;W. Brandner;Y. Clénet;C. Deen;E. Gendron;A. Huber;R. Klein;W. Laun;R. Lenzen;V. Naranjo;U. Neumann;J. Ramos;R. Rohloff;P. Yang;F. Eisenhauer;A. Amorim;K. Perraut;G. Perrin;C. Straubmeier;E. Fedrigo;M. Suárez Valles
重力是VLT干涉仪的第二代仪器，旨在增强VLTI的近红外天体测量和光谱成像能力。结合来自四个望远镜的光束，重力将提供10微角秒量级的天体测量精度，4毫角秒的成像分辨率，以及中低分辨率的光谱干涉测量，使其性能远远超过目前的红外干涉能力。为了最大限度地提高重力的性能，将在每个VLT单元望远镜上实施自适应光学校正，以校正大气湍流的影响。为了实现这一目标，重力项目包括四个新的波前传感器(WFS)和近红外优化实时控制系统的开发计划。这些设备将使四个单元望远镜在1.4-2.4μm的范围内实现闭环自适应校正。这对于在光学明亮的参考源稀缺的地区实施自适应光学至关重要，例如银河中心。在这里，我们介绍了重力波前传感器的设计，并概述了在典型观测条件下期望的自适应光学性能。由于采用了新开发的SELEX/ESO萨菲拉电子雪崩光电二极管(EAPD)探测器，在近红外线提供快速读出和低噪声，预计在500赫兹的工作频率下，AO系统将实现400 nm的剩余波前误差。≤
GRAVITY is a second generation instrument for the VLT Interferometer, designed to enhance the near-infrared astrometric and spectro-imaging capabilities of VLTI. Combining beams from four telescopes, GRAVITY will provide an astrometric precision of order 10 micro-arcseconds, imaging resolution of 4 milli-arcseconds, and low and medium resolution spectro-interferometry, pushing its performance far beyond current infrared interferometric capabilities. To maximise the performance of GRAVITY, adaptive optics correction will be implemented at each of the VLT Unit Telescopes to correct for the e_ects of atmospheric turbulence. To achieve this, the GRAVITY project includes a development programme for four new wavefront sensors (WFS) and NIR-optimized real time control system. These devices will enable closed-loop adaptive correction at the four Unit Telescopes in the range 1.4-2.4 μm. This is crucially important for an e_cient adaptive optics implementation in regions where optically bright references sources are scarce, such as the Galactic Centre. We present here the design of the GRAVITY wavefront sensors and give an overview of the expected adaptive optics performance under typical observing conditions. Bene_ting from newly developed SELEX/ESO SAPHIRA electron avalanche photodiode (eAPD) detectors providing fast readout with low noise in the near-infrared, the AO systems are expected to achieve residual wavefront errors of 400 nm at an operating frequency of 500 Hz.≤