EXPERIMENTS ON ER3+ IN SRF2 .I. FLUORESCENCE QUANTUM EFFICIENCIES AND LIFETIMES

This paper is concerned with the measurement and interpretation of the variations in the quantum efficiences and lifetimes of four of the Er 3+ fluorescing levels in the 1%-10% concentration range in SrF 2 at the three fixed temperatures 300°, 77°, 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 4I13/2, 4I 11/2, 4F9/2, and 4S3/2 levels, only decay from the 4S3/2 level is strongly influenced by pair decay processes, and then, only at 300°K. The 4F9/2 decay processes are slightly affected by pair decays, while the remaining levels are basically free from such decay processes.