Luminescence properties and energy transfer mechanism of Er3+/Tm3+ co-doped tellurite glasses

► Er3+/Tm3+ co-doped tellurite glasses were prepared by melt-quenching method. ► Luminescence properties of samples with varied Tm3+ concentration were investigated. ► 1.85 μm fluorescence intensity improved evidently with an enhanced PAET. ► ET mechanism was investigated by evaluating micro-coefficient and phonon contribution. ► The prepared glass possesses a large amplification quality factor of Tm3+ at 1.85 μm.