Mid-infrared luminescence and energy transfer characteristics of Ho 3+/Yb 3+ codoped lanthanum–tungsten–tellurite glasses

Abstract

Ho 3+/Yb 3+ codoped lanthanum–tungsten–tellurite (TWL) glasses are prepared by melt-quenching method. The Judd–Ofelt intensity parameters ( Ω t t = 2, 4, 6), radiative transition rates, radiative lifetimes, and branching ratios of Ho 3+ are calculated based on the absorption spectrum to evaluate the spectroscopic properties of Ho 3+ 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 Ho 3+: 5I 7 → 5I 8 are calculated. The energy transfer processes of Yb 3+–Yb 3+ and Yb 3+–Ho 3+ are analyzed, the results show that the Yb 3+ ions can transfer their energy to Ho 3+ ions with large energy transfer coefficient, and a maximum efficiency of 84%.