Controlled Coupling of a Single Nanoparticle to a High-Q Microsphere Resonator

In this work, coupling of a single nanoparticle to a high-Q microsphere resonator was realized. The combination of a near-field optical microscope with a novel microsphere spectroscopy unit made it possible to completely control the modes of the microsphere and their coupling to a prism outcoupler. A single dye-doped bead attached to the end of a near-field probe allowed a controlled coupling to the modes of the microsphere. By using confocal techniques it was also possible to demonstrate the coupling of a single quantum emitter (CdSe/ZnS nanocrystal). Some promising results were obtained, concerning the coupling of two nanoparticles via photon exchange of shared high-Q modes.