Spectral modification of the Stokes line of a Raman-coupled three-level system in a cavity

We have investigated the spectral modification of the Raman Stokes line in the cavity version of Raman scattering where a three-level system in the Λ configuration interacts with an externally driven pump mode and a Stokes mode in a cavity. Anti-Stokes modes are eliminated by the cavity-resonance condition. At very low intensities the spectrum consists of a single-peak structure (Raman Stokes) that splits into a doublet when the external pump field is sufficiently intense so that the effective Rabi frequency exceeds the rate of spontaneous emission. At very high intensity, however, a triplet structure appears where the strong sidebands are symmetrically separated from the central weak band