Spectral broadening and luminescence quenching of 1.53 μm emission in Er3+-doped zinc tellurite glass

The emission spectra and the lifetime of the lasing transition 4I13/2→4I15/2 in Er3+-doped TeO2-ZnO binary glass have been studied. The investigation includes Raman scattering spectroscopy as well as optical absorption, luminescence, and lifetime measurements techniques. The influence of erbium concentration on the line-shape of this electron transition has been analyzed. It was observed that the increasing of Er3+ ion concentration, in the 0.2-4 mol% range, results in a structural changes and a significant spectral broadening of the 1.53 μm emission band. Reabsorption has been evoked to explain the broadening of the 4I13/2→4I15/2 emission line. In the paper, is also reported the effect of the erbium content on the emission intensity of the 4I13/2→4I15/2 transition as well as on the lifetime of the 4I13/2 level. Based on the electrical-dipole interaction theory, the luminescence concentration quenching mechanism by hydroxyl groups is analyzed. The data suggest that <10% of hydroxyl groups are coupled to erbium ions in the zinc tellurite glass network.