Abstract
Rare earth-doped tellurite glasses are very attractive materials for laser and photonic applications, such as optical amplifiers. They have a good glass stability which leads to an enhancement of the radiative transition. In the present study, a new transparent bulk glass with the composition 85TeO(2)-5Nb(2)O(5)-5ZnO-5LiF doped with 1% Er2O3 (TNZL doped with Er3+) was prepared by using the conventional melt-quenching method. The thermal stability and the crystallization behavior of the glass were investigated using Differential Scanning Calorimetry (DSC), X-ray diffraction and Raman spectroscopy. Furthermore, UV-vis-NIR spectra were determined. From these Judd-Ofelt parameters, Omega(k) (k = 2, 4, 6) of Er3+ were evaluated. The oscillator strength type transition probabilities, spectroscopic quality factors, branching ratio and radiative lifetimes of several excited states of Er3+ were predicted using intensity Judd-Ofelt parameters. The down conversion, up conversion and near infrared luminescence of the Er3+ ions in TNZL glass were investigated. Green and red emissions corresponding to (H-2(11/2), S-4(3/2)) -> I-4(15/2) and F-4(9/2) -> I-4(15/2) transitions were observed. (C) 2014 Elsevier B.V. All rights reserved.