Energy transfer and cooperative processes in Yb3+-doped cubic sesquioxide laser ceramics and crystals

A comparative discussion of the spectroscopic and energy transfer properties of the Yb3+ ion in single crystals and transparent ceramics of cubic sesquioxide materials is presented. The spectroscopic studies of Yb3+ and of other rare earth ions co-doped with Yb3+ in transparent ceramic sesquioxides with ceramic grains of tens of microns show that the variety of structural centres of the doping ions and the distribution of the doping ions in these centres as well as the crystal field interaction, the electron–phonon interaction and the energy transfer processes in these materials are similar to those from single crystals. The cooperative absorption and emission of Yb3+ in transparent Sc2O3 ceramics, facilitated by the very suitable packing of the cationic sites, corresponds to the trends observed in the crystalline materials, showing that no obvious agglomeration of Yb3+ in these ceramics takes place.