Laser guide star facility developments at W. M. Keck Observatory

Laser Guide Star (LGS) facilities for adaptive optics (AO) have been in routine scientific operation on the Keck II and Keck I telescopes since 2004 and 2012, respectively. Two upgrades are currently in process for the Keck II LGS facility: moving the launch of the laser from the side of the Keck telescope to behind the secondary mirror and replacing the existing dye laser with a Raman-fiber amplifier (RFA) laser. Both of these upgrades are on the path to a multi-LGS facility for Keck’s next generation AO (NGAO) system. We will discuss the performance and operations experience with the existing LGS facilities with an emphasis on the newer Keck I LGS facility, the recently implemented Keck II center launch system and its initial on-sky results, the progress on the design and implementation of the new fiber laser, and the plans for a multi-LGS facility for NGAO.