Spectroscopic characterization of Ho3+ ion-doped fluoride glass

Among the new optical materials available, fluoride glass, which has an extended transmission window, is emerging as an important material for use in optical fibers, lasers, sensors, etc. Here, we analyze the spectroscopic properties of Ho3+ ions in a fluoroindate glass based on absorption measurements. Ho3+-doped fluoroindate glass with the composition (40 − x)InF3–20SrF2–20ZnF2–16BaF2–2GdF3–2NaF–xHoF3, x = 1.0, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0 and 9.0 mol%, was prepared under an argon atmosphere. Absorption spectra in the range 300–2200 nm were then obtained. The experimental oscillator strength fExp. was calculated from the areas under absorption bands. Using Judd–Ofelt theory and least-squares fitting, the phenomenological intensity parameter Ωλ (λ = 2, 4, 6) and the theoretical oscillator strength fCal. were calculated. To evaluate potential applications and to analyze the properties of Ho3+ ions in these host glasses, the following spectroscopy parameters were calculated: the transition probability between multiplets AJJ′, the branching ratio βJJ′, the radiative lifetime τR, the peak cross-section for stimulated emission σp, and the emitting-level multiphonon rate WNR for each band. The results were compared with those reported in the literature for similar glasses of the same concentration.