Optimization of 4.81 W Yb:YAG/1 030 nm thin disc laser

The laser diode array (LDA) pumped Yb:YAG thin disc laser has been analysed and optimized. The Yb:YAG disc with 10 mm diameter and 340 μm thickness was employed. The Yb3+ atom fraction is 10%. It was mounted onto the micro-channel copper heat sink by Cr/Au/In. The four-pass optical coupling system was well designed with two spherical imaging mirrors which have a diameter of 30 mm and radius of curvature of 50 mm. The pump-beam radius was calculated by LightTools Software. Considering mode matching, the output mirror which has radius of curvature 200 mm was employed. When the incident power was 18.73 W, a CW output power of 4.81 W at 1 030 nm was obtained. The optical conversion efficiency was 25.7%.