Even with incoherent driving, coherence effects may show up in the spontaneous emissions of an atom. We derive a general master equation and predict that for both the three-level V and \ensuremath{\Lambda} systems the intensity correlation function ${\mathit{g}}^{(2)}$ (\ensuremath{\tau}) may exhibit pronounced oscillations with frequency \ensuremath{\delta}\ensuremath{\omega} if the level separation \ensuremath{\Elzxh}\ensuremath{\delta}\ensuremath{\omega} is small. We obtain a marked difference in the beat amplitude for a single \ensuremath{\Lambda} system as compared to a beam or gas. If \ensuremath{\delta}\ensuremath{\omega} is much smaller than the natural linewidth we find dark and light periods in the spontaneous emission.Even with incoherent driving, coherence effects may show up in the spontaneous emissions of an atom. We derive a general master equation and predict that for both the three-level V and \ensuremath{\Lambda} systems the intensity correlation function ${\mathit{g}}^{(2)}$(\ensuremath{\tau}) may exhibit pronounced oscillations with frequency \ensuremath{\delta}\ensuremath{\omega} if the level separation \ensuremath{\Elzxh}\ensuremath{\delta}\ensuremath{\omega} is small. We obtain a marked difference in the beat amplitude for a single \ensuremath{\Lambda} system as compared to a beam or gas. If \ensuremath{\delta}\ensuremath{\omega} is much smaller than the natural linewidth we find dark and light periods in the spontaneous emission.

Physical Review AMar 1, 199367 citations

{\mathit{g}}^{(2)}

(\ensuremath{\tau}) may exhibit pronounced oscillations with frequency \ensuremath{\delta}\ensuremath{\omega} if the level separation \ensuremath{\Elzxh}\ensuremath{\delta}\ensuremath{\omega} is small. We obtain a marked difference in the beat amplitude for a single \ensuremath{\Lambda} system as compared to a beam or gas. If \ensuremath{\delta}\ensuremath{\omega} is much smaller than the natural linewidth we find dark and light periods in the spontaneous emission.