THEORY OF GENERALIZED DAMPING AND QUANTUM INTERFERENCE IN MULTILEVEL ATOMIC SYSTEMS

When a monochromatic laser resonantly excites a multi-level atom the o ptical Bloch equations for the reduced atomic density matrix, which de scribe the evolution of such a system, may exhibit generalized damping terms. We justify the origin of these damping terms within the radiat ive cascade description of resonance fluorescence in the dressed-atom picture and in the spin-orbit coupling picture. We describe the connec tion between generalized damping terms and quantum interference in the process of spontaneous emission.