Thermal and laser properties of Yb:LuAG for kW thin disk lasers

Thin disk laser experiments with Yb:LuAG (Yb:Lu3Al5O12) were performed leading to 5 kW of output power and an optical-to-optical efficiency exceeding 60%. Comparative analyses of the laser relevant parameters of Yb: LuAG and Yb:YAG were carried out. While the spectroscopic properties were found to be nearly identical, investigations of the thermal conductivities revealed a 20% higher value for Yb: LuAG at Yb3+-doping concentrations of about 10%. Due to the superior thermal conductivity with respect to Yb: YAG, Yb: LuAG offers thus the potential of improved performance in high power thin disk laser applications. (C) 2010 Optical Society of America