Spectral properties and dynamics of luminescent states of Pr3+ and Tm3+ in lead borate glasses modified by PbF2

A heavy metal oxide borate glass with composition (70-x)PbO-18B(2)O(3)-6Al(2)O(3)-3WO(3) (wt%) was modified by variable content of PbF2 (x = 9 36 and 72 wt%) and doped with 1 wt% of Pr3+ or Tm3+ ions. The influence of the PbF2 content on optical properties and luminescence dynamics has been observed through the variation of an effective line width of D-1(2) -> H-3(4) and (1)G(4) -> F-3(4) emissions as well as the D-1(2) and (1)G(4) lifetimes of Pr3+ and Tm3+, respectively. It was observed that the increase of PbF2 content leads to narrowing of the D-1(2) -> H-3(4) band from 680 to 590cm(-1.) This effect was not observed for the (1)G(4) -> F-3(4) thulium emission. The variation of luminescence kinetics was observed both for Pr3+ - and Tm3+-doped samples; the increase of the PbF2 content has changed the D-1(2) lifetime from 13.8 to 16.5 mu s and from 34 to 43 mu s for the (1)G(4) level. (c) 2006 Elsevier B.V. All rights reserved.