Broadband near-infrared luminescence property in Nd3+/Tm3+ co-doped tellurite glass

Abstract

The near-infrared (NIR) band luminescent characteristics of tellurite glasses doped with Nd3+ and Tm3+ ions synthesized by melt-quenching conventional technology were explored. Differential scanning calorimetry (DSC) curves, Raman spectra, X-ray diffraction (XRD) patterns, absorption spectra, fluorescence spectra and fluorescence decay curves were measured. The XRD patterns demonstrated the amorphous state structural nature of the prepared glasses, the various structural units such as TeO4, TeO3+1, TeO3, BiO6, ZnO4, WO6 and WO4 were determined by Raman spectra, and DSC curves revealed the excellent thermal stability of glass host with ΔT of 150 °C. Based on the Judd-Ofelt theory, the transition probabilities and fluorescence branching ratios of the Nd3+:4F3/2→4I13/2 and Tm3+:3H4→3F4 transitions corresponding to 1.33 µm and 1.47 µm band emissions were (570.56 s−1, 10.94 %) and (320.75 s−1, 8.17 %), respectively. Under excitation at 808 nm laser diode (LD), the spectral overlap of these two bands produced a relatively flat and broadband fluorescence spectra located primarily at S + E band region with the full width at half maximum (FWHM) of 201 nm, which could provide an effective supplement to the present C + L-band of Er3+. The broadband luminescence mechanism of Nd3+ and Tm3+ ions and the interactions between them were discussed.