29 July 2010 Pyramid wavefront sensing with a laser guide star for an ELT
Author Affiliations +
Proceedings Volume 7736, Adaptive Optics Systems II; 773657 (2010); doi: 10.1117/12.856720
Event: SPIE Astronomical Telescopes + Instrumentation, 2010, San Diego, California, United States
Abstract
The wavefront sensor [WFS] is a key element of an Adaptive Optics [AO] system. It gives access to a direct measurement of the turbulent phase, its curvature or its slope, from which the mirror voltages are computed. The ability of the system to correct efficiently the atmospheric turbulence is strongly dependent on the performance of the WFS in estimating the turbulent phase. The Shack-Hartmann [SH] WFS has been for a long time the standard used in AO systems. In 1996, it has been proposed1 a new generation WFS, the pyramid WFS. It is a focal plane WFS, based on the principle of a Foucault knife-edge. It has been demonstrated that it provides a consistent gain with respect to the Shack-Hartmann.2,5-7 More recently, improvements were proposed to increase the pyramid performance.3, 4 On the framework of the developpement of extremely large telescopes, the interest of a pyramid wave front sensor appears clearly. But its behaviour with laser guide stars [LGS], most probably necessary in any Extremely Large Telescope [ELT], is still relatively unknown. Some WFS dedicated to LGS wave front sensing has already been proposed8,9 but a full study of the pyramid WFS behaviour is still necessary. This work's aim is to bring answers to this topic.
© (2010) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Brice Le Roux, "Pyramid wavefront sensing with a laser guide star for an ELT", Proc. SPIE 7736, Adaptive Optics Systems II, 773657 (29 July 2010); doi: 10.1117/12.856720; https://doi.org/10.1117/12.856720
PROCEEDINGS
5 PAGES


SHARE
KEYWORDS
Modulation

Wavefront sensors

Laser guide stars

Adaptive optics

3D metrology

Phase shift keying

Sodium

Back to Top