∼2 μm fluorescence radiative dynamics and energy transfer between Er3+ and Tm3+ ions in silicate glass

•A Er3+/Tm3+ co-doped silicate glass with good thermal stability (kgl = 0.402 for STE glass) is prepared.•Efficient ∼2 μm emission is observed under 808 nm and 980 nm laser excitation.•The glass structure and spectroscopic properties are confirmed by optical absorption, IR transmission, Raman and fluorescence studies.•The content of OH groups deceases efficiently after fluorine ions are introduced.•The energy transfer coefficient from Er3+ to Tm3+ in STFE glass is 13.39 × 10−40 cm6/s.

A Er3+/Tm3+ co-doped silicate glass with good thermal stability is prepared by melt-quenching method. An efficient emission of ∼2 μm is observed under different selective laser excitations. The optical absorption and transmission spectra, Raman spectra, and emission spectra are tested to characterize ∼2 μm emission properties of Er3+/Tm3+ co-doped silicate glasses and a reasonable energy transfer mechanism of ∼2 μm emission between Er3+ and Tm3+ ions is proposed. Based on the optical absorption spectra, the Judd–Ofelt parameters and radiative properties were calculated. Intense ∼2 μm emission is obtained from Er3+/Tm3+ co-doped silicate glasses due to the efficient energy transfer from Er3+ to Tm3+ ions. The energy transfer coefficient from Er3+ to Tm3+ ions can reach as high as 13.39 × 10−40 cm6/s. In addition, the population of the OH groups is decreased and the ∼2 μm emission is effectively enhanced with fluoride introduction. The emission property, together with good thermal property, indicates that Er3+/Tm3+ co-doped silicate glass is a potential kind of laser glass for efficient ∼2 μm laser.

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