Application of modified Judd–Ofelt theory and the evaluation of radiative properties of Pr3 +-doped lead telluroborate glasses for laser applications

Praseodymium doped lead telluroborate (PTBPr) glasses were prepared by conventional melt quenching method. The absorption spectra have been analyzed to evaluate the intensity parameters applying the standard and the modified Judd–Ofelt theories. The emission spectra under 3P2 level excitation (λex = 447 nm) were investigated to estimate the laser characteristic parameters. These emission measurements together with Judd–Ofelt intensity parameters (Ωλ = 2,4,6) have been used to calculate the radiative transition probabilities, fluorescence branching ratios and radiative lifetimes of the transitions from 3P0 and 1D2 levels to their lower lying levels. The quenching of fluorescence intensity and experimental lifetime with the increase of Pr3 + concentration and the shift of 1D2 → 3H4 emission peak towards longer wavelengths was discussed. The non-radiative losses due to multiphonon and energy transfer relaxations were also explained. The Commission Internationale de IʹEclairage (CIE) coordinates, color purity and optical band gap energy values were evaluated. Some of the basic laser characteristics such as stimulated emission cross-section, optical and bandwidth gain parameters and fluorescence quantum efficiency were also reported.