Photon-photon correlations from a resonantly driven quantum dot in a microcavity

We demonstrate strongly driven resonance fluorescence from a single~InGaAs quantum dot in a planar microcavity by measuring the oscillatory second-order correlation function, $g^{(2)}(t)$, of the photoluminescence. Resonance fluorescence is emission from a coherently and resonantly~excited two-level quantum system and under strong CW excitation the system undergoes one or more Rabi oscillations before emitting.~ These oscillations are observed in $g^{(2)}(t)$ rather than the simple anti-bunching dip caused by incoherent excitation. This behavior shows, along with other measurements, that the quantum dot is~well-described by a simple two-level model even at high excitation intensities.~ The dot is resonantly excited with a laser via the waveguide mode of the microcavity and the emission couples into the Fabry-Perot mode where it is collected. The~ability to perform coherent manipulations on a single quantum emitter is a critical step on the~road to many quantum optical devices including high efficiency indistinguishable single photon sources.