Design and experiment of multi-pass pump system for Yb:YAG thin-disk laser

The design of a 16 pass pump system for Yb:YAG thin-disk laser has been presented. The model of the system was built and simulated. Experiments based on the system using one disk cooled with water through micro channel were done. The disk was homemade, with the diameter of 10 mm, thickness of 250 μm and doping atom fraction of 10%. For the pump power of 69.5 W, when a reflector with the radius of curvature of －800 mm is used, 24.4 W 1 030 nm continuous output is achieved, with optical to optical conversion efficiency of 38.8%; when a reflector with the radius of curvature of －2 000 mm is used, 18.65 W 1 030 nm continuous output is achieved, with the beam quality factor no more than 1.1 and optical to optical conversion efficiency of 26.8%．