Spectroscopy and diode-pumped laser oscillation of Yb3+, Ho3+-doped yttrium scandium gallium garnet

We report on the laser oscillation of Yb3+, Ho3+-doped yttrium scandium gallium garnet around 1.2 and 3 mu m under laser diode excitation. At 1208 nm output powers of up to 135 mW and slope efficiencies up to 7.6% with respect to the incident pump power were achieved at room temperature under continuous wave excitation. Quasicontinuous wave excitation led to laser emission at 2844 nm with pulse energies up to 10 m.J. The laser relevant spectroscopic data, i.e., lifetimes, absorption, and emission cross sections are given and the excited state absorption spectrum is presented. (C) 2000 American Institute of Physics. [S0021- 8979(00)07909-3].