Energy transfer between chromium and neodymium ions in a mixed fluorophosphate glass [21.74Al(${\mathrm{PO}}_3$${)}_3$-57.${8\mathrm{B}\mathrm{a}\mathrm{F}}_2$-16.${96\mathrm{A}\mathrm{l}\mathrm{F}}_3$] has been investigated in the 4.2–300 K temperature range by using steady-state and time-resolved laser spectroscopy. Radiative and nonradiative energy transfer has been demonstrated from the time-resolved emission spectra and the decrease of the ${\mathrm{Cr}}^{3+}$ lifetimes. Comparison between time-resolved emission spectra for ${\mathrm{Cr}}^{3+}$ singly doped and codoped samples with different ${\mathrm{Nd}}^{3+}$ concentrations shows that the radiative transfer is linearly dependent on ${\mathrm{Nd}}^{3+}$ concentration. The nonradiative energy transfer is consistent with an electric-dipole–electric-dipole interaction mechanism. Good agreement is found if transfer efficiency corrected for Nd-Nd self-quenching is compared with the measured sensitized ${\mathrm{Nd}}^{3+}$ luminescence. The transfer efficiency of a ${\mathrm{Cr}}^{3+}$, ${\mathrm{Nd}}^{3+}$ system in the investigated fluorophosphate glass has also been compared with previous results in a pure fluoride glass giving a higher efficiency for the fluorophosphate glass if the ${\mathrm{Nd}}_2$${\mathrm{O}}_3$ concentration is kept below 2 wt %.

• Received 21 April 1993

DOI:https://doi.org/10.1103/PhysRevB.48.2941