Spectroscopy and energy transfer in lead borate glasses doubly doped with Tm3+ and Dy3+ ions

Lead borate glasses singly and doubly doped with Tm3+ and Dy3+ were prepared by traditional melt-quenching technique. The emission spectra of rare earths in studied glass systems were registered under different excitation wavelengths. The observed emission bands are located in the visible spectral region. They correspond to D-1(2) -> F-3(4) (blue) and (1)G(4) -> H-3(6) (blue) transitions of Tm3+ as well as F-4(9/2) -> H-6(15/2) (blue), E-4(9/2) -> H-6(13/2) (yellow) and F-4(9/2) -> H-6(11/2) (red) transitions of Dy3+. Moreover, the energy transfer process from Tm3+ to Dy3+ was observed. The luminescence bands originating to characteristic transitions of thulium and dysprosium ions are present on emission spectra under direct excitation of Tm3+. Luminescence lifetimes for the excited states of Tm3+ and Dy3+ ions in lead borate glass were also determined based on decay measurements. The luminescence intensities and lifetimes depend significantly on the relative concentrations of the optically active dopants. (C) 2017 Elsevier B.V. All rights reserved.