Mid-infrared luminescence and energy transfer characteristics of Ho3+/Yb3+ codoped lanthanum–tungsten–tellurite glasses

Ho3+/Yb3+ codoped lanthanum–tungsten–tellurite (TWL) glasses are prepared by melt-quenching method. The Judd–Ofelt intensity parameters (Ωt t = 2, 4, 6), radiative transition rates, radiative lifetimes, and branching ratios of Ho3+ are calculated based on the absorption spectrum to evaluate the spectroscopic properties of Ho3+ in TWL glass. The mid-infrared emission of the samples are investigated under the excitation of 980 nm LD. The absorption, emission cross-sections and gain coefficient of Ho3+:5I7 → 5I8 are calculated. The energy transfer processes of Yb3+–Yb3+ and Yb3+–Ho3+ are analyzed, the results show that the Yb3+ ions can transfer their energy to Ho3+ ions with large energy transfer coefficient, and a maximum efficiency of 84%.