Experiments on Er3+ in SrF2. I. Fluorescence Quantum Efficiencies and Lifetimes

Abstract

This paper is concerned with the measurement and interpretation of the variations in the quantum efficiences and lifetimes of four of the Er³⁺ fluorescing levels in the 1%–10% concentration range in SrF₂ at the three fixed temperatures 300°, 70°, and 4.2°K. The interpretation has centered on the identification of the nature of ion–ion interactions present in the samples, and the establishment of their importance in the decay processes. The results show that of the four fluorescing levels studied, that is, the ${}^4{I}_{\text{13/2}}$ , ${}^4{I}_{\text{11/2}}$ , ${}^4{F}_{\text{9/2}}$ , and ${}^4{S}_{\text{3/2}}$ levels, only decay from the ${}^4{F}_{\text{3/2}}$ level is strongly influenced by pair decay processes, and then, only at 300°K. The ${}^4{F}_{\text{9/2}}$ decay processes are slightly affected by pair decays, while the remaining levels are basically free from such decay processes.