Quantum Optics With Integrated Plasmonic/Optical Systems

We present an experimental observation of strong optical coupling between individual, nanocrystal CdSe/ZnS quantum dots, and the guided surface plasmon modes of a proximal silver nanowire. The plasmonic excitation is then evanescently coupled to the modes of an adjacent Si$_3$N$_4$ waveguide aligned parallel to the wire, resulting in high collection efficiency. The strong coupling between emitter and field is enabled by the unique properties of the plasmon modes on the nanowires. In particular, due to the small size of the nanowires ($\sim$100nm in diameter), the surface plasmons are localized transversely to dimensions well below the diffraction limit. Efficient out-coupling of the plasmon-enhanced quantum dot emission and photon correlations consistent with a single-photon source are observed.