Energy transfer processes in rare-earth-ion-doped materials

Energy transfer characteristics for Yb3+ to Tm3+ ions have been investigated in order to carry out characterization of the host materials and to obtain proper improvement procedures for the conventional rate equation model. Experimental investigations were carried out particularly for YAG as the host material and the results were compared with the results obtained for several fluoride lattices. It has been shown that the energy transfer coefficient from Yb3+ to Tm3+ ions is larger and more strongly dependent upon Yb3+ ion concentration in YAG than in the fluoride lattices. These experimental results have been compared with the results of Monte Carlo simulation carried out on a microscopic model. The dependence of the energy transfer coefficient on the donor concentration as well as that upon the host materials are explained systematically with the microscopic model. (C) 2000 Elsevier Science B.V. All rights reserved.