Visible and mid-infrared spectral emissions and radiative rates calculations of Tm3+ doped BBLC glass.

Quaternary glasses with the composition 75Li2B2O7-(15-x)BaO-10CdO-xTm2O3 (BBLC) (0 ≤ x ≤ 2 mol %) have been prepared by melt-quenching method. The structure changes, the absorption coefficient of OH- and the maximum phonon energy of these glasses are studied by FT-IR spectra. Optical and emission properties of Tm3+ doped BBLC glasses have been investigated at room temperature. The optical band gap (Eopt), dispersion parameters and Urbach's energy (Eu) of the prepared samples have been estimated. Judd-Ofelt theory has been applied to obtain the radiative rates and optical intensity parameters. Oscillator strengths, radiative lifetimes, and branching ratio of different transitions have been calculated. Derived emission cross sections of the emission transitions in the visible range are determined. A strong emission is observed at 455 nm, this line is attributed to 1D2→3F4. Spectral line in the blue region has been observed at wavelength of 515 nm, as well. Two central wavelengths of 1.2 µm and 1.8 µm, which are located in the short- and mid- wave IR spectral regions, are analyzed. These emissions are attributed to the transitions 3H5→3H6 and 3F4→3H6, respectively.