Spectroscopic properties of Nd3+-doped tungsten–tellurite glasses

• Nd3+-doped TeO2–WO3 glasses with low OH content were prepared.
• Tellurite glasses prepared in O2-rich atmosphere using a vacuum furnace.
• The cross-relaxation was the main loss mechanism in fluorescence.
• Good agreement was observed in the luminescence quantum efficiency.

In this work, we investigate the spectroscopy properties of neodymium doped tungsten–tellurite glasses prepared in ambient and O2-rich atmospheres. A conversion of TeO4 to TeO3 units was caused by the addition of Nd3+ into the glass, which was confirmed by absorption spectra and by Judd–Ofelt parameter behavior. The relaxation of the 4F3/2 level is dominated by radiative decay and cross-relaxation between Nd3+ and Nd3+ ions. The energy transfer from Nd3+ to the hydroxyl group is negligible when compared to the cross-relaxation. The luminescence quantum efficiency values of the 4F3/2 level decreases as the Nd3+ concentration increases, independently if determined by the Judd–Ofelt method or by the thermal lens technique. The observed reduction in the IR absorption associated to OH groups was not effective to improve the luminescence quantum efficiency.