Upconversion luminescence of Er3+-doped oxyfluoride tellurite glass

In this work, Er3+-doped oxyfluoride tellurite glasses have been prepared and their spectral properties have been studied, and the mechanisms of upconversion luminescence have been also investigated. The bright green emission can be observed by naked eye at room temperature under 980 nm diode laser excitation. Three blue luminescence bands centered at 410, 452 and 490 nm corresponding to the H-2(9/2)-> I-4(15/2), F-4(5/2,3/2)-> I-4(15/2) and F-4(7/2)-> I-4(15/2) transitions of Er3+ can be simultaneously observed. By analyzing the difference of luminescence lifetime between indirect excitation of 980 nm tunable laser and direct excitation of 488 nm xenon lamp, the mechanisms of upconversion luminescence was discussed. It indicates the energy transfer play an important role in Er3+-doped oxyfluoride tellurite glasses.