Abstract

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 a collection of two-level atoms shows this doublet and, for sufficiently high intensities, its evolution into a single peak. As the excitation increases anharmonicity grows in the oscillators to a point where frequency hysteresis appears in the transmission spectrum. The saturation of the transition of the two-level atoms is responsible for the nonlinearity that causes the anharmonicity. This work investigates the transition from the doublet into the singlet. We include the possibility of a detuning between the atomic and cavity resonances. The detuning decreases the coupling between two oscillators and modifies the regions of hysteresis. The stability of the different solutions is analyzed as the parameters of atomic and cavity detuning vary. The model is extended to include the experimentally relevant transverse profile of the cavity mode as well as the standing wave structure of the field. Hu's same evolution of the vacuum Rabi doublet has been the subject of recent investigations in semiconductor microcavities. Although the transmitted spectrum at low intensity shows the same vacuum Rabi splitting, the underlying mechanism is very different.

© 1996 Optical Society of America