Spectroscopic investigations of the Er3+ fluorescence transitions at 540 nm and 1.5 µm in fluoride phosphate and phosphate glasses

Abstract

Fluoride phosphate glasses with different phosphate contents and metaphosphate glasses, both with different Er3+ concentrations of 3 to 10 ∙ 10^19 cm^-3, were prepared. The lifetimes and the intensities of the fluorescence transitions 4S3/2 → 4I15/2 at 540 nm and 4I13/2 → 4I15/2 at 1.5 µm have been studied as a function of phosphate content and Er3+ concentration. The results have been discussed by considering the rates of radiative decay, multiphonon relaxation, cross relaxation and energy transfer to hydroxyl groups. Furthermore, laser action of some fluoride phosphate glasses via krypton ion laset pumping was achieved.