Interference between a fluorescent photon and a classical field: An example of nonclassical interference

Abstract

Fluorescent photons emitted from an atom will interfere with a classical field only if the atom is not in a pure excited state. This is a strictly quantum-mechanical condition, which can be tested, in principle, by allowing the light emitted from an atom undergoing Rabi oscillations to interfere with the coherent pumping field. The theory of this process is discussed.