On-chip excitation of nanodiamonds embedded in plasmonic waveguides

Quantum emitters can be integrated in monolithic nanoscale plasmonic circuitry via low-loss plasmonic configurations to confine light well below the diffraction limit. In integrated quantum plasmonics, waveguides based on surface plasmon polariton (SPP) modes that propagate electromagnetic waves along metal-dielectric or metal-air interfaces are superior to dielectric-based (and therefore diffraction-limited) photonic waveguides. The observation is in respect to the available Purcell enhancement from embedded quantum emitters and the ongoing trend toward on-chip integration and miniaturization to realize optical signal processing and integrated circuits. Different metal-dielectric configurations have been developed for strong light-matter interactions at the scale of the single photon to support the propagation of plasmonic modes confined beyond the diffraction limit. The property can enable unique prospects to design highly integrated photonic-signal processing systems, sensors and optical imaging techniques with nanoscale resolution.