Controlled excitation of diamond color centers using low-loss dielectric-loaded surface plasmon polariton waveguides

Controlled placement and excitation of quantum emitters in plasmonic nanostructures is highly desired for efficient plasmon-emitter interfaces on a chip. We present a hybrid approach for direct energy exchange between propagating surface plasmons and quantum emitters using low-loss dielectric-loaded surface plasmon polariton waveguides (DLSPPWs). Alignment of the waveguides axes is pre-determined to maximize emitter decay into fundamental DLSPPW mode. Lithographic fabrication is performed on negative high-resolution electron-beam resist to incorporate nanodiamonds containing single nitrogen-vacancy (NV) centers. Efficient grating couplers at the two ends of the waveguide facilitate input coupling of excitation light and output coupling of the NV emission. The hybrid platform provided a controlled activation of NV emitter micrometers away from the host nanodiamond and can be further expanded to include several quantum emitters, revealing the potential of our approach for realization of functional on-chip quantum plasmonics.