Excitation of the transition ${}_{}{}^3{}_{}{}^{}$${\mathit{H}}_4$${\to }^1$${\mathit{D}}_2$ in a ${\mathrm{Pr}}^{3+}$-doped fluoroindate glass at ∼588 nm results in efficient blue emission at ∼480 nm which is ascribed to the ${}_{}{}^3{}_{}{}^{}$${\mathit{P}}_0$${\to }^3$${\mathit{H}}_4$. The upconversion process is due to an energy transfer involving a pair of ${\mathrm{Pr}}^{3+}$ ions. The dynamical behavior of the anti-Stokes emission is described using a rate-equation model which allows one to obtain the energy-transfer rates involving the pair states which contribute to the upconversion process.

• Received 19 July 1994

DOI:https://doi.org/10.1103/PhysRevB.50.16219