Spectroscopy of Nd3+ ions in new rare-earth-rich fluoroarsenate glasses

Rare-earth-rich fluoroarsenate glasses were synthesized in the Na2O, As2O5, BaF2, YF3 system. Physical constants are given for the most stable compositions. The effects of neodymium ions in the (40Na(4)As(2)O(7)-30BaF(2)-30YF(3)) mol% glass were investigated in terms of emission spectroscopy and lifetime measurements as a function of temperature and concentration. Time-resolved line-narrowed fluorescence spectra of the F-4(3/2) --> I-4(9/2) transition show that energy transfer occurs between non-resonant sites. A quantitative measure of the transfer as a function of time indicates that a dipole-dipole mechanism dominates. In addition, the transfer rate is found to increase with increasing excitation energy, that is with increasing number of possible energy accepters. (C) 1999 Elsevier Science B.V. All rights reserved.