Dependence of the Yb3+ emission cross section and lifetime on temperature and concentration in yttrium aluminum garnet

Measurements are reported of the spectroscopic properties (absorption and emission spectra, stimulated-emission cross section, and radiative lifetime) of (YbxY1-x)(3)Al5O12 for nominal x values of 0.025, 0.05, 0.1, 0.2 and 0.3 at temperatures of 15-300 K. The emission cross sections of Yb:YAG with different Yb 31 concentrations were determined by use of the Fuchtbauer-Ladenburg formula and the reciprocity method. At low temperatures, the product (sigmatau) of the effective stimulated-emission cross section and the radiative lifetime is greater than at room temperature for all concentrations. Product sigmatau is nearly independent of Yb3+ concentration at a given temperature. These results will aid in the design of high-power thin disk lasers by use of highly doped Yb:YAG. (C) 2003 Optical Society of America.