Near-field modulation of single photon emitter with a plasmonic probe

Single solid-state quantum dots have significant potential as bright single-photon sources for scalable photonic quantum information technologies. Engineering their radiative relaxation properties is of significant importance for their practical applications. In this study, we demonstrate a cavity-free, broadband approach for modulating and collecting the fluorescence of a single-photon emitter using a fiber taper-silver nanowire plasmonic probe. When the plasmonic probe is located above a single colloidal quantum dot at approximately 20 nm, the photon-emitter interaction increased rapidly and a significant decrease, by an average factor of 3.38, in the lifetime of the quantum dot was observed. The fluorescence signal of the quantum dots was collected by the hybrid probe, with significantly higher efficiency than that of the traditional metal-coated near-field probe. The results of the numerical simulation were in good agreement with the experimental results. The proposed near-field modulation method can be applied to other single-photon sources and proved to be a flexible method for manipulating the luminescence of systems based on single-photon emitters.