Comparative spectroscopic investigation of rare earth-doped oxide transparent ceramics and single crystals

The high-resolution optical spectroscopy and emission decay of rare earth-doped garnet and sesquioxide polycrystalline transparent ceramics produced by solid-state synthesis, with grains of tens of microns, indicate that the nature, variety, and distribution of structural centers formed by the doping ions, their quantum states (energy levels, transition probabilities) and the energy transfer processes are similar to those reported for the corresponding single crystals. New systems based on simple- or multiple-doped Sc2O3 ceramics indicate that these materials show potential for new laser materials in conventional or sensitised emission schemes.