Improved performance of the laser guide star adaptive optics system at Lick Observatory

摘要

Abstract: Results of experiments with the laser guide staradaptive optics system on the 3-meter Shane telescopeat Lick Observatory have demonstrated a factor of 4performance improvement over previous results. Stellarimages recorded at a wavelength of 2 $mu@m werecorrected to over 40 percent of the theoreticaldiffraction-limited peak intensity. For the previoustwo years, this sodium-layer laser guide star systemhas corrected stellar images at this wavelength toapproximately 10 percent of the theoretical peakintensity limit. After a campaign to improve the beamquality of the laser system, and to improve calibrationaccuracy and stability of the adaptive optics systemusing new techniques for phase retrieval andphase-shifting diffraction interferometry, the systemperformance has been substantially increased. The nextstep will be to use the Lick system for astronomicalscience observations, and to demonstrate this level ofperformance with the new system being installed on the10-meter Keck II telescope. !12