Share Email Print
cover

Proceedings Paper

A near-infrared tip-tilt sensor for the Keck I laser guide star adaptive optics system
Author(s): Peter Wizinowich; Roger Smith; Roberto Biasi; Sylvain Cetre; Richard Dekany; Bruno Femenia-Castella; Jason Fucik; David Hale; Chris Neyman; Dietrich Pescoller; Sam Ragland; Paul Stomski; Mario Andrighettoni; Randy Bartos; Khanh Bui; Andrew Cooper; John Cromer; Marcos van Dam; Michael Hess; Ean James; Jim Lyke; Hector Rodriguez; Thomas Stalcup
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

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.

Paper Details

Date Published: 21 July 2014
PDF: 12 pages
Proc. SPIE 9148, Adaptive Optics Systems IV, 91482B (21 July 2014); doi: 10.1117/12.2055279
Show Author Affiliations
Peter Wizinowich, W. M. Keck Observatory (United States)
Roger Smith, California Institute of Technology (United States)
Roberto Biasi, Microgate S.r.l. (Italy)
Sylvain Cetre, W. M. Keck Observatory (United States)
Richard Dekany, California Institute of Technology (United States)
Bruno Femenia-Castella, W. M. Keck Observatory (United States)
Jason Fucik, California Institute of Technology (United States)
David Hale, California Institute of Technology (United States)
Chris Neyman, W. M. Keck Observatory (United States)
Dietrich Pescoller, Microgate S.r.l. (Italy)
Sam Ragland, W. M. Keck Observatory (United States)
Paul Stomski, W. M. Keck Observatory (United States)
Mario Andrighettoni, Microgate S.r.l. (Italy)
Randy Bartos, California Institute of Technology (United States)
Khanh Bui, California Institute of Technology (United States)
Andrew Cooper, W. M. Keck Observatory (United States)
John Cromer, California Institute of Technology (United States)
Marcos van Dam, Flat Wavefronts (New Zealand)
Michael Hess, W. M. Keck Observatory (United States)
Ean James, W. M. Keck Observatory (United States)
Jim Lyke, W. M. Keck Observatory (United States)
Hector Rodriguez, California Institute of Technology (United States)
Thomas Stalcup, W. M. Keck Observatory (United States)


Published in SPIE Proceedings Vol. 9148:
Adaptive Optics Systems IV
Enrico Marchetti; Laird M. Close; Jean-Pierre Véran, Editor(s)

© SPIE. Terms of Use
Back to Top