Determination of the energy transfer parameters in modeling the luminescence kinetics of Er3+ and Yb3+ ions in fluorophosphate glasses with a low phosphate content

Abstract

The fluorophosphate glasses with composition of Ba(PO3)2 – AlF3–CaF2 – MgF2–BaF2 – SrF2–YbF3 – ErF3 were synthesized and their spectroscopic properties were studied. The main attention here was paid to studying the luminescence kinetics Yb3+ (1040 nm) and Er3+ (1550 nm, 655 nm and 540 nm). It has been found that the population of the 4I13/2 (Er3+) level and the relaxation of the 2F5/2 (Yb3+), 4F9/2, and 2H11/2+4S3/2 (Er3+) levels are close to exponential and the probabilities of these processes are well approximated by linear functions with respect to the ytterbium concentration. All this led to the conclusion that the migration-accelerated energy transfer makes a significant contribution to the population and deactivation of these energy levels. A scheme of the main energy transfer channels in an ensemble of ytterbium and erbium ions and the corresponding system of rate equations are proposed. On the basis of these equations, mathematical modeling of the luminescence kinetics of ytterbium and erbium ions was carried out and the energy transfer parameters were estimated.