Rabi-splitting and photon-number squeezing due to excitons in microcavities

First, nonlinear optical responses of excitons in microcavities are shown to depend strongly on the relative magnitude of inhomogeneous width of excitons and the Rabi frequency. Abrupt disappearance of Rabi-splitting is expected as function of pump power for small inhomogeneous broadening while quartet structures are observable for strongly inhomogeneous system. Second, combined effect of this Rabi-oscillation and excitonic nonlinearity is shown to induce the photon-number squeezing sequentially in some time regions with a photon-coherent state as an initial one.