Wilhelm Rainer, Luong Bruno, Courteville Alain, Estival Sébastien, Gonté Frédéric, Schuhler Nicolas
FOGALE nanotech, 125, Rue de l'Hostellerie, 30900 Nîmes, France.
Appl Opt. 2008 Oct 10;47(29):5473-91. doi: 10.1364/ao.47.005473.
We present a noncontact optical metrology measuring the pistons and tip/tilt angles of the 61 hexagonal segments of a compact-sized segmented mirror. The instrument has been developed within the scope of a design study for the European Extremely Large Telescope (E-ELT). It is used as reference sensor for cophasing of the mirror segments in closed-loop control. The mirror shape is also measured by different types of stellar light-based phasing cameras whose performances will be evaluated with regard to a future E-ELT. Following a description of the system architecture, the second part of the paper presents experimental results demonstrating the achieved precision: 0.48 nm rms in piston and 74 nrad rms in tip/tilt.
我们展示了一种非接触式光学计量方法，用于测量紧凑型拼接镜61个六边形镜段的活塞位移以及倾斜和俯仰角度。该仪器是在欧洲极大望远镜（E-ELT）设计研究范围内开发的。它被用作闭环控制中镜段共相的参考传感器。镜形也由不同类型的基于星光的相位相机测量，其性能将针对未来的E-ELT进行评估。在描述了系统架构之后，本文第二部分展示了实验结果，证明了所达到的精度：活塞位移的均方根误差为0.48纳米，倾斜和俯仰的均方根误差为74纳弧度。
