EXCITED-STATE DYNAMICS AND ENERGY TRANSFERS IN (CA, ZR)-SUBSTITUTED GD3GA5O12 SINGLE-CRYSTALS DOPED WITH CR-3+ AND TM-3+ IONS

The excited-state dynamics of Cr3+ and Tm3+ ions in (Ca, Zr)-substituted Gd3Ga5O12 garnets and the energy transfer mechanisms between these impurity ions were studied at room temperature under various laser excitations. The single crystals have been grown in our laboratory by using the Czochralski method under nitrogen and oxygen flow. The Cr3+-->Tm3+ energy transfers and the Tm3+-->Tm3+ cross-relaxation processes were analysed in detail and their efficiencies calculated as a function of the Tm3+ concentrations.