Vacuum Rabi splitting through nonlinear and linear interactions in microcavities

Vacuum Rabi splitting phenomena are discussed in detail based on the semiclassical laser theory. We show that splitting observed in the cavity transmission spectrum gives reciprocal information on the Rabi flopping induced by excited atoms inside a single-resonant-mode cavity. However, for a multi-resonant-mode cavity, observing the transmission peak splitting does not assure the reciprocal Rabi flopping. We also show that temporally oscillatory behavior in transmitted light with pulsed-light-prob-ing, and even the splitting observable in the spontaneous emission spectrum so far reported with planar microcavities, are well explained by spectrum filtering under linear light-matter interaction regimes.