Optical Free-Induction Decay in LaF3:Pr3+

Abstract

The dephasing time of coherently prepared ${\mathrm{Pr}}^{3+}$ impurity ions in a La ${\mathrm{F}}_3$ crystal is measured by optical free-induction decay. Above 4°K, phonon processes severely shorten the decay time. Below 4°K, we observe a temperature-independent decay time of 0.38 μsec. This is surprisingly short considering that there are no contributions from first-order hyperfine, phonon, or ${\mathrm{Pr}}^{3+}$-${\mathrm{Pr}}^{3+}$ interactions.