Nonradiative losses in Yb:KGd(WO4)2 and Yb:Y3Al5O12

Photothermal deflection spectroscopy was used to measure nonradiative losses in Yb:KGW and Yb:YAG (for both crystal and for the first time in ceramic form). Fluorescent quantum efficiencies for both materials were found to be greater than 98.9%. The reduction of nonradiative losses due to annealing of Yb:YAG is also presented.