This paper provides the first experimental test of the Bloch equations for an optical transition in a low-temperature impurity-ion solid, ${\mathrm{Pr}}^{3+}$ : La ${\mathrm{F}}_{3}$ , where the condition ${T}_{1}\ensuremath{\gg}{T}_{2}$ applies. Intensity-dependent optical free-induction-decay measurements are performed by use of an ultrastable cw dye laser (linewidth, 300 Hz) and reveal an $\mathrm{exp}(\ensuremath{-}\frac{2t}{{T}_{2}})$ decay law at low Rabi frequency ($\ensuremath{\chi}$), as predicted by the Bloch equations, and an $\mathrm{exp}(\ensuremath{-}\ensuremath{\chi}t)$ decay at high $\ensuremath{\chi}$, which violates the Bloch prediction but agrees with Redfield's characterization of NMR saturation in solids.This paper provides the first experimental test of the Bloch equations for an optical transition in a low-temperature impurity-ion solid, ${\mathrm{Pr}}^{3+}$: La${\mathrm{F}}_{3}$, where the condition ${T}_{1}\ensuremath{\gg}{T}_{2}$ applies. Intensity-dependent optical free-induction-decay measurements are performed by use of an ultrastable cw dye laser (linewidth, 300 Hz) and reveal an $\mathrm{exp}(\ensuremath{-}\frac{2t}{{T}_{2}})$ decay law at low Rabi frequency ($\ensuremath{\chi}$), as predicted by the Bloch equations, and an $\mathrm{exp}(\ensuremath{-}\ensuremath{\chi}t)$ decay at high $\ensuremath{\chi}$, which violates the Bloch prediction but agrees with Redfield's characterization of NMR saturation in solids.

Physical Review LettersApr 25, 1983197 citations

Tests of the Optical Bloch Equations for Solids

Ralph G. DeVoe, Axel Schenzle, Masaharu Mitsunaga +1 more

An optical coherence phenomenon–power- dependent optical line narrowing—is reported for the first known time. The effect is observed in a low-temperature impurity- ion solid, Pr3+:LaF3, using a coherent transient technique for which saturation conditions prevail. Current theories of saturation, based on the optical Bloch equations or on rate equations, fail to explain our experimental results. We have therefore developed a microscopic coherence theory that introduces dephasing into the density-matrix equations of motion in a manner equally valid at low and high power and that agrees closely with our experimental results. This work thus represents the first reported observation of the failure of the optical Bloch equations in a low-temperature impurity-ion solid.An optical coherence phenomenon–power- dependent optical line narrowing—is reported for the first known time. The effect is observed in a low-temperature impurity- ion solid, Pr3+:LaF3, using a coherent transient technique for which saturation conditions prevail. Current theories of saturation, based on the optical Bloch equations or on rate equations, fail to explain our experimental results. We have therefore developed a microscopic coherence theory that introduces dephasing into the density-matrix equations of motion in a manner equally valid at low and high power and that agrees closely with our experimental results. This work thus represents the first reported observation of the failure of the optical Bloch equations in a low-temperature impurity-ion solid.

Jun 18, 19840 citations

This paper provides the first experimental test of the Bloch equations for an optical transition in a low-temperature impurity-ion solid,

{\mathrm{Pr}}^{3+}

: La

{\mathrm{F}}_{3}

, where the condition ${T}_{1}\ensuremath{\gg}{T}_{2}$ applies. Intensity-dependent optical free-induction-decay measurements are performed by use of an ultrastable cw dye laser (linewidth, 300 Hz) and reveal an $\mathrm{exp}(\ensuremath{-}\frac{2t}{{T}_{2}})$ decay law at low Rabi frequency ($\ensuremath{\chi}$), as predicted by the Bloch equations, and an $\mathrm{exp}(\ensuremath{-}\ensuremath{\chi}t)$ decay at high $\ensuremath{\chi}$, which violates the Bloch prediction but agrees with Redfield's characterization of NMR saturation in solids.