Thermomechanical properties of Yb3+ doped laser crystals: Experiments and modeling.

Thermal conductivity values of several laser materials were determined by photothermal measurements and compared to predicted values. The effect of the ytterbium doping concentration could be modeled using a simple cationic mass difference model. For ytterbium content corresponding to an absorption coefficient of 10 cm^-1 (or 85% absorption of the pump power) Yb:GdVO₄ (c-axis) and Yb:Gd₃Ga₅O₁₂ laser materials present the highest measured thermal conductivity values of 8.1 W m^-1 K^-1 and 7.7 W m^-1 K^-1, respectively. Yb:Y₃Al₅O₁₂, Yb:Lu₃Al₅O₁₂, Yb:CaGdAlO₄, and Yb:YAlO₃ belong to the 6-7 W m^-1 K^-1 range while Yb:CaF₂ and Yb:Lu₂SiO₅ are situated in the 5-6 W m^-1 K^-1 range. Other matrices such as Yb:SrLaGa₃O₇, Yb:CaGdAl₃O₇, Yb:SrGdGa₃O₇, and Yb:BaLaGa₃O₇ have thermal conductivity values lower than 5 W m^-1 K^-1. With the knowledge of the thermal conductivities and the determination of the thermal expansion coefficients, thermal shock parameters are evaluated for several ytterbium doped laser hosts. [ABSTRACT FROM AUTHOR]