Spectroscopic and photoluminescence characteristics of Dy 3+ ions in lead containing sodium fluoroborate glasses for laser materials

Abstract

Lead containing calcium zinc sodium fluoroborate (LCZSFB) glasses doped with different concentrations of trivalent dysprosium ions were prepared and investigated by the XRD, FTIR, optical absorption, photoluminescence and decay curve analysis. The experimentally determined oscillator strengths have been determined by measuring the areas under the absorption peaks and the Judd–Ofelt (J–O) intensity parameters were calculated using the least squares fit method. From the evaluated J–O parameters the radiative transition probability rates, radiative lifetimes and branching ratios were calculated for 4F 9/2 excited level. Room temperature photoluminescence spectra for different concentrations of Dy 3+-doped LCZSFB glasses were obtained by exciting the glass samples at 386 nm. The intensity of Dy 3+ emission spectra increases with increasing concentration of 0.1, 0.25, 0.5 and 1.0 mol% and beyond 1.0 mol% the concentration quenching is observed. The measuring branching ratios are reasonably high for transitions 4F 9/2→ 6H 15/2 and 6H 13/2, suggesting that the emission at 484 and 576 nm, respectively, can give rise to lasing action in the visible region. From the visible emission spectra, yellow–blue ( Y/ B) intensity ratios and chromaticity color coordinates were also estimated. The lifetimes of 4F 9/2 metastable state for the samples with different concentrations were also measured and discussed.