Judd-Ofelt parameters, hypersensitivity, and emission characteristics of Ln(3+) (Nd3+, Ho3+, and Er3+) ions doped in PbO-PbF2 glasses

The Judd-Ofelt parameters, Omega(2), and Sigma Omega(lambda), (lambda = 2, 4, 6), for Nd3+, Ho3+, and Er3+ doped in the oxyfluoride glass 30PbO . 70Pb F(2) lie intermediate between fluoride glasses and oxide glasses such as be rate and phosphate glasses, providing evidence for the sensitivity of these parameters to the bonding environment. The variation of Omega(2), unlike O mega(4), and Omega(6), for the lanthanide series is qualitatively different for glass matrices compared to crystalline matrices. Plots of oscillator s trengths of hypersensitive transitions for these ions against Sigma Omega(l ambda) (lambda = 2, 4, 6) are found useful in discerning the degree of hype rsensitivity of these transitions due to change in the host matrix, The F-5 (2) K-3(8) (5)G(6) <-- I-5(8) transition of Ho3+ is found to be the most hy persensitive. The radiative parameters for the oxyfluoride glasses are clos e to fluoride glasses and the branching ratio of the important lasing trans ition, viz,, F-4(3/2) --> I-4(11/2), of Nd3+ is higher for the present case compared to fluoride glass. The results suggest that the oxyfluoride glass es may be used as hosts in the place of fluoride glasses wherever suitable as they are more stable and easy to prepare and have similar radiative prop erties.