Spectroscopic properties of Ho3+ and Tm3+ in Ca3Sc2Ge3O12 crystals

Single crystals of the Ca3Sc2Ge3O12 (CaSGG) garnet activated with Ho3+ and Tm3+ have been grown by the 'flux growth' technique. The absorption spectra, the visible emission properties and the decay curves of the excited states have been measured at 10 and 298 K. The room temperature absorption spectra have been analyzed in the framework of the Judd-Ofelt theory and the 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 using the calculated intensity parameters, and the results have been compared with the experimental data in order to estimate the efficiency of the non-radiative processe