Effects of dispersion forces in optical resonance phenomena

Abstract

We study the effect of dispersion forces (dipole-dipole interaction) on the resonance fluorescence and on the absorption spectrum of a two-atom system undergoing cooperative evolution under the action of an external coherent driving field. We find that the dipole-dipole interaction is responsible for splitting the usual Rabi sideband of the resonance fluorescence spectrum into a doublet, and for enhancing the height of the additional peaks located at twice the Rabi frequency from the resonance. The absorption spectrum is also modified when the atomic separation is sufficiently small.