2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/108008We study the probe spectrum of light generated by spontaneous emission into the mode of a cavity QED system. The probe spectrum has a maximum on-resonance when the number of inverted atoms for an input drive is maximal. For a larger number of atoms N, the maximum splits and develops into a doublet, but its frequencies are different from those of the so-called vacuum Rabi splitting.4 pages, 4 figuresQuantum Physicstext