Spectroscopic characterization and laser performance of Pr,Mg:CaAl_12O_19

Abstract

We report on the crystal growth, spectroscopic investigations, and the demonstration of visible laser operation of $\mathrm{Pr},\mathrm{Mg}\text{:}{\mathrm{CaAl}}_{12}{\mathrm{O}}_{19}$. Crystals with dopant concentrations of 1 and 6 at. % were grown by the Czochralski method. Polarization-dependent ground-state absorption and emission spectra as well as the excited state absorption characteristics were recorded in the visible spectral region. Furthermore, the decay dynamics of the ${}^3{\mathrm{P}}_0$ manifold and the radiative lifetime were determined. By employing a 6 at. % doped $\mathrm{Pr},\mathrm{Mg}\text{:}{\mathrm{CaAl}}_{12}{\mathrm{O}}_{19}$ crystal as gain medium and a frequency doubled optically pumped semiconductor laser as pump source, cw laser operation was realized at 644.3 and at 725.2 nm. Maximum output powers and slope efficiencies exceeded 320 mW and 25%, respectively.