Er3+ doped germanate-tellurite glass for mid-infrared 2.7 μm fiber laser material

•We report a series of different concentration Er3+ doped germanate-tellurite (GT) glass compositions to study mid-infrared spectroscopic properties.•In parallel, the energy transfer microparameters of 4I11/2 and 4I13/2 level are calculated and examined.•The fluorescence lifetime of the samples are tested by exciting at 540 nm laser modulated by a signal generator.

2.7 μm fluorescence has been achieved in the different concentration Er3+ doped germanate-tellurite glasses. The germanate-tellurite glass shows a good thermal stability and Fourier transform infrared spectra indicates that the mid-infrared transmission spectra performance is good. Based on the measured absorption spectra, the Judd-Ofelt parameters were calculated and discussed. Moreover, the emission spectra of Er3+ doped glasses show that the emission intensity at ~2.7 μm reaches a maximal value and no obvious concentration quenching phenomenon happens even if the ErF3-doping concentration is 1.5 mol%. In addition, the 2.7 μm radiative transition probability and emission cross section is 35.57 s−1 and 13.87×10−21 cm2 corresponding to the Er3+:4I11/2→4I13/2 transition and superior gain performance was also obtained from the prepared glass. Meanwhile, energy transfer mechanism has been investigated in detail. Hence, the spectroscopic characteristics as well as the good thermal property indicate that this kind of glass is an attractive host for developing mid-infrared fiber laser.