A curvature-based laser guide star adaptive optics system for Gemini-South

The Gemini Observatory and University of Hawaii are planning to install an 85-element curvature adaptive optics sytem with a laser guide star system on its Cerro Pachon telescope in 2001. This paper discusses the motivation, issues on implementing a laser guide star with a curvature-based system, the implementation of a laser guide star based on a commercially available 2W ring-dye laser, and the expected performance of the system. Detailed simulations show very promising results for system performance down to natural guide star magnitudes of 19-20(th) magnitude. The performance cross-over point between NGS and LGS is between 13-16th magnitude depending on the performance parameter of interest (e.g. Strehl, energy through a slit, etc.).