PHOTON CORRELATIONS IN THE SPECTRUM OF A SUPERRADIANT SYSTEM IN A STRONG CAVITY FIELD

We investigate correlations among photons from the components of the resonance fluorescence spectrum of a cooperative system of two-level atoms interacting with a strong field of a single-mode lossless cavity. The properties of the central band are more closely related to the superradiant effect in free space than the sidebands. The central band field has reduced fluctuations and the collective dipole has its largest uncertainty when half the atoms are initially excited. Partial atomic excitation destroys the sub-Poissonian character of the sideband field and leads to a bunching-antibunching transition in the correlation of a sideband photon followed by a central band photon.