Abstract

In a recent publication¹ the question of the possibility of observing directly the quantum jumps associated with the excitation and deexcitation of an atomic electron in a three-level transition was considered. While the analysis of Ref. ¹ reveals the manner in which the fluorescence from a strong transition of a lifetime T₁ is modulated by the absorption and emission processes of a weak transition of lifetime T₂ (T₁ ≪ T₂), it was restricted to the case of incoherent excitation of the two transitions. The purpose of the present work is to reconsider this problem for monochromatic excitation in which a variety of coherent effects come into play. The analysis proceeds in a straightforward fashion in the Heisenberg representation to yield expressions for field and atomic correlation functions representing probabilities for the detection of successive photons from the same transition as well as for cross correlations of emission probabilities. In the limit of T₁ ≪ T₂, a coarse graining of time with respect to the strong transition produces expressions analogous to those presented in Ref. ¹. The roles of Autler-Townes splitting, frequency detuning, and saturation of the weak transition are discussed.

© 1985 Optical Society of America