Spectroscopic and luminescence characteristics of erbium doped TNZL glass for lasing materials

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 85TeO2-5Nb2O5-5ZnO-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, Ωk (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 (2H11/2, 4S3/2) → 4I15/2 and 4F9/2 → 4I15/2 transitions were observed.