 Power Spectrum of Light Scattered by Two-Level Systems by B. R. Mollow

Published in Physical Review 188, starting at page 1969, on 25 December 1969: journals.aps.org/pr/abstract/10.1103/PhysRev.188.1969

The primary calculation obtains the near-resonant driven-atom fluorescence spectrum from two-time atomic dipole correlations, with radiation damping included through coupling to the quantized electromagnetic field. It provides the source for the Mollow triplet.