Analytical solution for the spectrum of resonance fluorescence of a cooperative system of two atoms and the existence of additional sidebands

The analytical solution for the spectrum of resonance fluorescence from a collective system of two atoms is presented. It is shown that the spectrum is a decreasing function of frequency in the neighborhood ω-ωL=±2Ω (Ω is the Rabi frequency) for moderately large Ω and exhibits resonant structure only for extremely large Ω≈100γ. For moderately large Ω the resonant contributions at ω-ωL=±2Ω are destroyed by the nonresonant contributions; hence the additional structures at ±2Ω can be resolved only by filtering the nonresonant contributions.