-2 μ m broadband luminescence in Tm3+/Ho3+/Er3+-doped tellurite glass

Improving the broadband luminescent properties in-2 mu m band has always been a serious challenge. This paper proposed a Tm3+, Ho3+ and Er3+ doped combination in tellurite glass, which was synthesized through melt- quenching and characterized by a series of physical and spectral tests. Firstly, tellurite glass of Tm3+-Ho3+ co-doping produced a-2 mu m broadband luminescence ranging from 1570 to 2200 nm with FWHM (full width at half maximum) of 379 nm under 808 nm pumping. This broadband luminescence originated from 3 F 4 to 3 H 6 level transition of Tm3+ and 5 I 7 to 5 I 8 level transition of Ho3+. Furthermore, after adding an appropriate amount of Er3+, the luminescent intensity was improved by 116 %, mainly attributed to the direct or indirect energy transfers from Er3+ to Tm3+ and Ho3+ ions. Calculations of Judd-Ofelt spectroscopic parameters and gain cross- sections supported the results obtained from Tm3+/Ho3+/Er3+ doped tellurite glass in-2 mu m band. In addition, DSC (differential scanning calorimetry) curves exhibited excellent thermal stability, XRD (X-ray diffraction) patterns and Raman spectra disclosed the non-crystalline and network structural units of the synthesized tellurite glasses. The findings in this work demonstrate that tellurite glass with Tm3+, Ho3+ and Er3+ combination is an efficient strategy which can be applied in-2 mu m band ultra-short pulse lasers and broadband amplifiers.