Simulation Study Of On Sky Performance Of A New 20w Class Macro-Micro Pulse Laser For Sodium Laser Guide Star

As one crucial component for the latest generation of adaptive optics, tremendous efforts have been put into the development of high performance 20 W class sodium laser guide star laser system. Two such systems, the continuous wave laser by Toptica, and the quasi-continuous pulse laser by TIPC were extensively studied with simulation and field tests. A new type of 20 W class sodium laser, macro-micro pulse laser, is currently being developed by CIOMP. In this paper, we will study its on-sky performance with simulation based on Monte Carlo rate equation method. The predicted coupling efficiency for this laser in the zenith direction in Changchun is 179.73 photons s(-1) W-1/(atoms m(-2)). The variation of coupling efficiency of this type of laser with pointing direction and the effect of D2b repumping are also studied and reported in this paper.