EVOLUTION OF THE VACUUM RABI PEAKS IN A MANY-ATOM SYSTEM

The two peaks of the vacuum Rabi splitting behave like simple harmonic oscillators for very weak excitation. The transmission spectrum of a cavity filled with two-level atoms shows this doublet at low values of the driving intensity, but only a single peak at high values. The evo lution from a doubler to a singlet is governed by the anharmonic respo nse of the system as the driving intensity increases. The anharmonicit y can grow to a point where frequency hysteresis appears in the transm ission spectrum. This work investigates theoretically with a semiclass ical model the transition from the doubler into the singlet. The stabi lity of the different solutions is analysed as the parameters of atomi c and cavity detuning vary. The model is extended to include the exper imentally relevant transverse profile of the cavity mode as well as th e standing wave structure of the field.