An estimation of the distribution functions of doped Tb 3+ and Nd 3+ in glasses by fluorescence measurements

Abstract

The distribution functions of doped Tb 3+ and Nd 3+ in silicate, germanate, borate and phosphate glasses, in which cross-relaxation among active ions plays an important role, have been estimated by fluorescence measurements. In order to analyze both the steady state and the transient fluorescence characteristics, a non-linear model for the resonant energy transfer has recently been developed. The experimental fluorescence intensity and decay curves, measured as a function of acceptor concentration, suggested a modified distribution function, which included the effect of the segregation of donors and acceptors. The number of segregated Tb 3+ ions at the second nearest neighbor position around a Tb 3+ ion was estimated to be 0.1–3.4, depending on the host glass.