Optical spectroscopy and fluorescence dynamics of Er3+ in Ca3Sc2Ge3O12 crystal

The absorption and luminescence spectra of Er3-doped Ca3Sc2Ge3O12 single crystals have been measured at various temperatures from 10 to 298 K. The decay times of the lower-lying excited states, emitting in the visible and the near-IR regions, have been measured as a function of temperature. From the oscillator strengths of the absorption transitions, the Judd–Ofelt intensity parameters have been evaluated. The spontaneous-transition probabilities, the branching ratios, and the radiative lifetimes have been determined for the most important emitting states by use of the calculated intensity parameters, and the results have been compared with the experimental data. The stimulated-emission cross sections have been estimated for the most important laser transitions, indicating that this compound can be considered a suitable active medium for laser operation.