CR3-]ND3+ ENERGY-TRANSFER IN FLUOROPHOSPHATE GLASS INVESTIGATED BY TIME-RESOLVED LASER SPECTROSCOPY()

Energy transfer between chromium and neodymium ions in a mixed fluorop hosphate glass [21.74Al(PO3)3-57.8BaF2-16.96 AlF3] has been investigat ed in the 4.2-300 K temperature range by using steady-state and time-r esolved laser spectroscopy. Radiative and nonradiative energy transfer has been demonstrated from the time-resolved emission spectra and the decrease of the Cr3+ lifetimes. Comparison between time-resolved emis sion spectra for Cr3+ singly doped and codoped samples with different Nd3+ concentrations shows that the radiative transfer is linearly depe ndent on Nd3+ concentration. The nonradiative energy transfer is consi stent with an electric-dipole-electric-dipole interaction mechanism. G ood agreement is found if transfer efficiency corrected for Nd-Nd self -quenching is compared with the measured sensitized Nd3+ luminescence. The transfer efficiency of a Cr3+, Nd3+ system in the investigated fl uorophosphate glass has also been compared with previous results in a pure fluoride glass giving a higher efficiency for the fluorophosphate glass if the Nd2O3 concentration is kept below 2 wt %.