The origin of spectral broadening of 1.53 μm emission in Er3+-doped zinc tellurite glass

The emission spectra of the lasing transition 4I13/2→4I15/2 in Er3+-doped TeO2–ZnO binary glass have been studied. The influence of the concentration of Er2O3 and sample-thickness on the line-shape of this electron transition has been analyzed. The investigation includes Raman scattering spectroscopy as well as optical absorption and photoluminescence. 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 as a main mechanism to explain the broadening of the 4I13/2→4I15/2 emission line.