Collecting quantum dot fluorescence with a hybrid plasmonic probe

Collecting quantum emitter fluorescence with high efficiency and high spatial resolution is a crucial topic in quantum and nanophotonic fields. In the general cases of far-field objective lens collection, though the collection efficiency can be very high, the spatial resolution is diffraction limited. Or one can use near-field probe, such as metal-coated dielectric tips, to break this diffraction limit, while the collection efficiency is very low. In this work, a new method is proposed to collect the fluorescence of quantum dots (QDs) with a fiber-integrated silver nanowire (AgNW) waveguide. Fluorescence lifetime measurement is performed to investigate the coupling between QDs and different plasmonic modes. Compared with previous near-field collection methods, the AgNW-fiber probe can realize much higher collection efficiency with similar spatial resolution. This fiber-integrated plasmonic probe may be useful in the area of fluorescence imaging and is also promising for quantum information devices. (c) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement