Characterization of Tm³⁺ doped TNZL glass laser material

In this paper, a new tellurite glass (85TeO₂·5.0Nb₂O₅·5.0ZnO·5.0LiF) doped with 1 mol% Tm₂O₃ was prepared by melt-quenching technique. Differential scanning calorimetry (DSC) measurements indicate a good thermal stability, X-ray diffraction patterns show no sign of crystallization. Precise refractive index measurements were performed on five different wavelengths by a prism spectrometer. The optical energy gap, the Sellmeier energy gap and the dispersion energy were estimated. Judd–Ofelt intensity parameters were evaluated in order to obtain electric and magnetic-dipole transition probabilities, branching ratios and radiative lifetimes of several excited states of Tm³⁺. The classical McCumber theory was used to evaluate the emission cross-sections for the ³F₄→³H₆ transition at a wavelength of around 1.8 µm. The characteristics of down-conversion luminescence in the visible range were studied by exciting Tm³⁺ ions into the ¹G₄ level. Furthermore the structure of this glass was analyzed by Raman spectroscopy. - Highlights: • A new thermally stable tellurite glass (TNZL doped 1 mol% Tm³⁺) was synthesized by a melt-quenching method. • A complete Judd–Ofelt spectroscopic evaluation of the TNZL:Tm glass is presented. • A high gain coefficient and emission cross section are obtained for Tm³⁺ in TNZL glass in the 1.8 μm region. • The TNZL:Tm glass would be a potential laser operation around 1.8 μm emission. • TNZL:Tm is a good candidate for generate a blue light for color display devices and light emitting diodes