Physical review. B, Condensed matter
Spectral and temporal dynamics of nonequilibrium phonons in LaF3 : Pr3+
W. A. Tolbert, William M. Dennis, William M. Yen
Abstract
Defect-induced one-phonon absorption is used to generate high-occupation-number narrow-band nonequilibrium phonon populations at a range of frequencies in ${\mathrm{LaF}}_{3}$:${\mathrm{Pr}}^{3+}$. The spectral and temporal dynamics associated with the return to equilibrium of these phonons is observed. Processes that dominate the spectral evolution are shown to be narrow-band phonon confluence, anharmonic decay, and the broadband confluence of anharmonic decay products. The experimental data are shown to be in good agreement with a phonon-occupation-number rate-equation analysis that incudes the above processes.