On-demand positioning of a preselected quantum emitter on a fiber-coupled toroidal microresonator

The coupling of a quantum emitter to the modes of a silica toroid is presented. A fiber taper is used to manipulate and transfer a preselected diamond nanocrystal onto the toroid. Optical coupling of few nitrogen vacancy (NV) color centers contained inside the nanocrystal to the resonator modes is demonstrated by detecting the fluorescence via a tapered optical fiber coupler. A clear antibunching in the photon correlation measurement is observed indicating emission from only six NV centers residing inside the nanocrystal. The latter is confirmed by a photoluminescence spectrum at liquid helium temperature resolving individual zero phonon lines. (C) 2009 American Institute of Physics. [doi:10.1063/1.3243989]