Deterministic photon cascade from resonant two-photon excitation of a single InAs quantum dot

We demonstrate the coherent creation of a biexciton in an InAs/GaAs quantum dot embedded in a planar microcavity through resonant two-photon excitation. This results in laser scattering-free cascaded single photons with excellent two-photon suppression. We also observe Rabi oscillations, Ramsey interference and high indistinguishability. This scheme can be used to generate entangled photon pairs and heralded single photons.