Erbium doped tellurite glasses (TeO 2 + Li 2 O + TiO 2) were prepared by conventional melt-quenching method to study the influence of the Er 3+ concentration on the luminescence quantum efficiency (g) at 1.5 lm. Absorption and luminescence data were used to characterize the samples, and the g parameter was measured using the well-known thermal lens spectroscopy. For low Er 3+ concentration, the mea-sured values are around 76%, and the concentration behavior of g shows Er–Er and Er–OH À interactions, which agreed with the measured lifetime values. Ó 2013 Elsevier B.V. All rights reserved.