TY - JOUR A1 - Essmann, M. A1 - Becker, S. F. A1 - Witt, Julia A1 - Zhan, J. A1 - Chimeh, A. A1 - Korte, A. A1 - Zhong, J. A1 - Vogelgesang, R. A1 - Wittstock, G. A1 - Lienau, C. T1 - Vectorial near-field coupling N2 - The coherent exchange of optical near fields between two neighbouring dipoles plays an essential role in the optical properties, quantum dynamics and thus the function of many naturally occurring and artificial nanosystems. These interactions are challenging to quantify experimentally. They extend over only a few nanometres and depend sensitively on the detuning, dephasing and relative orientation (that is, the vectorial properties) of the coupled dipoles. Here, we introduce plasmonic nanofocusing spectroscopy to record coherent light scattering spectra with 5 nm spatial resolution from the apex of a conical gold nanotaper. The apex is excited solely by evanescent fields and coupled to plasmon resonances in a single gold nanorod. We resolve resonance energy shifts and line broadenings as a function of dipole distance and relative orientation. We demonstrate how These phenomena arise from mode couplings between different vectorial components of the interacting optical near fields, specifically from the coupling of the nanorod to both transverse and longitudinal polarizabilities of the taper apex. KW - Plasmon resonance KW - Coherent exchange KW - Optical near field KW - Plasmonic nanofocusing spectroscopy PY - 2019 U6 - https://doi.org/10.1038/s41565-019-0441-y SN - 1748-3387 VL - 14 IS - 7 SP - 698 EP - 704 PB - Nature AN - OPUS4-48028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -