Application of standard and modified Judd–Ofelt theories to thulium doped fluoroindate glass

Fluoroindate glasses of the following compositions: (40–x)InF3–20ZnF2–16BaF2–20SrF2–2GdF3–2NaF–xTmF3 with x=1,3 mol% were prepared in a dry box under an argon atmosphere. The absorption spectra at room temperature in the spectral range 350–2200 nm were obtained. The spectra obtained for each sample had similar absorption and only the amplitude of the different bands changed as the concentration of Tm3+. The experimental oscillator strengths were determined from the areas under the absorption bands. Using the standard and modified Judd–Ofelt theory, intensity parameters Ωλ (λ=2,4,6) and (λ=2,3,4,5,6), respectively for f–f transitions of Tm3+ ions as well as transition probabilities, branching ratios and radiative lifetimes for each band were determined. The results are compared with those of other glasses described in the literature.