Controlled photon transfer between two individual nanoemitters via   shared high-Q modes of a microsphere resonator
  We realize controlled cavity-mediated photon transfer between two single nanoparticles over a distance of several tens of micrometers. First, we show how a single nanoscopic emitter attached to a near-field probe can be coupled to high-Q whispering-gallery modes of a silica microsphere at will. Then we demonstrate transfer of energy between this and a second nanoparticle deposited on the sphere surface. We estimate the photon transfer efficiency to be about six orders of magnitude higher than that via free space propagation at comparable separations. 
S. Gotzinger, L. de S. Menezes, A. Mazzei, O. Benson, S. Kuhn, V.   Sandoghdar