SOLAR-PUMPED SOLID-STATE LASERS

Results are presented for direct solar pumping of a Nd:YAG rod laser. Stable CW output of more than 60 W was obtained with a slope efficiency exceeding 2%. A compound parabolic concentrator, designed to increase the solar radiation coupled into the laser rod, was used in these experiments. The results are consistent with predictions based on a single solar-pumped laser model, which is also presented. Using this model, it is shown that existing laser materials with broadband absorption characteristics (e. g. , alexandrite and Nd:Cr:GSGG) have a potential for better than 10% overall conversion efficiency when solar-pumped.