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.
Subscribe to Journal
Get full journal access for 1 year
only $8.25 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.
Ostroumov, E. E., Mulvaney, R. M., Cogdell, R. J. & Scholes, G. D. Broadband 2D electronic spectroscopy reveals a carotenoid dark state in purple bacteria. Science 340, 52–56 (2013).
Scholes, G. D., Fleming, G. R., Olaya-Castro, A. & van Grondelle, R. Lessons from nature about solar light harvesting. Nat. Chem. 3, 763–774 (2011).
Hildner, R., Brinks, D., Nieder, J. B., Cogdell, R. J. & van Hulst, N. F. Quantum coherent energy transfer over varying pathways in single light-harvesting complexes. Science 340, 1448–1451 (2013).
Unold, T., Mueller, K., Lienau, C., Elsaesser, T. & Wieck, A. D. Optical control of excitons in a pair of quantum dots coupled by the dipole–dipole interaction. Phys. Rev. Lett. 94, 137404 (2005).
Krenner, H. J. et al. Direct observation of controlled coupling in an individual quantum dot molecule. Phys. Rev. Lett. 94, 057402 (2005).
Biolatti, E., Iotti, R. C., Zanardi, P. & Rossi, F. Quantum information processing with semiconductor macroatoms. Phys. Rev. Lett. 85, 5647–5650 (2000).
Zhang, Y. et al. Visualizing coherent intermolecular dipole–dipole coupling in real space. Nature 531, 623–627 (2016).
Hettich, C. et al. Nanometer resolution and coherent optical dipole coupling of two individual molecules. Science 298, 385–389 (2002).
Kern, J. et al. Atomic-scale confinement of resonant optical fields. Nano Lett. 12, 5504–5509 (2012).
Deutsch, B., Hillenbrand, R. & Novotny, L. Visualizing the optical interaction tensor of a gold nanoparticle pair. Nano Lett. 10, 652–656 (2010).
Lovera, A., Gallinet, B., Nordlander, P. & Martin, O. J. F. Mechanisms of Fano resonances in coupled plasmonic systems. ACS Nano 7, 4527–4536 (2013).
Mühlschlegel, P., Eisler, H. J., Martin, O. J. F., Hecht, B. & Pohl, D. W. Resonant optical antennas. Science 308, 1607–1609 (2005).
Carminati, R., Greffet, J. J., Henkel, C. & Vigoureux, J. M. Radiative and non-radiative decay of a single molecule close to a metallic nanoparticle. Opt. Commun. 261, 368–375 (2006).
Chikkaraddy, R. et al. Single-molecule strong coupling at room temperature in plasmonic nanocavities. Nature 535, 127–130 (2016).
Dulkeith, E. et al. Fluorescence quenching of dye molecules near gold nanoparticles: radiative and nonradiative effects. Phys. Rev. Lett. 89, 203002 (2002).
Ha, T. et al. Probing the interaction between two single molecules: fluorescence resonance energy transfer between a single donor and a single acceptor. Proc. Natl Acad. Sci. USA 93, 6264–6268 (1996).
Haedler, A. T. et al. Long-range energy transport in single supramolecular nanofibres at room temperature. Nature 523, 196–U127 (2015).
Gaebel, T. et al. Room-temperature coherent coupling of single spins in diamond. Nat. Phys. 2, 408–413 (2006).
Dolde, F. et al. Room-temperature entanglement between single defect spins in diamond. Nat. Phys. 9, 139–143 (2013).
Steidtner, J. & Pettinger, B. Tip-enhanced Raman spectroscopy and microscopy on single dye molecules with 15 nm resolution. Phys. Rev. Lett. 100, 236101 (2008).
Zhang, R. et al. Chemical mapping of a single molecule by plasmon-enhanced Raman scattering. Nature 498, 82–86 (2013).
Dorfmüller, J. et al. Plasmonic nanowire antennas: experiment, simulation and theory. Nano Lett. 10, 3596–3603 (2010).
Savage, K. J. et al. Revealing the quantum regime in tunnelling plasmonics. Nature 491, 574–577 (2012).
Stockman, M. I. Nanofocusing of optical energy in tapered plasmonic waveguides. Phys. Rev. Lett. 93, 137404 (2004).
Ropers, C. et al. Grating-coupling of surface plasmons onto metallic tips: a nanoconfined light source. Nano Lett. 7, 2784–2788 (2007).
Neacsu, C. C. et al. Near-field localization in plasmonic superfocusing: a nanoemitter on a tip. Nano Lett. 10, 592–596 (2010).
Gramotnev, D. K. & Bozhevolnyi, S. I. Nanofocusing of electromagnetic radiation. Nat. Photon. 8, 14–23 (2014).
Schmidt, S. et al. Adiabatic nanofocusing on ultrasmooth single-crystalline gold tapers creates a 10-nm-sized light source with few-cycle time resolution. ACS Nano 6, 6040–6048 (2012).
Kravtsov, V., Ulbricht, R., Atkin, J. & Raschke, M. B. Plasmonic nanofocused four-wave mixing for femtosecond near-field imaging. Nat. Nanotechnol. 11, 459–464 (2016).
Vogelsang, J. et al. Ultrafast electron emission from a sharp metal nanotaper driven by adiabatic nanofocusing of surface plasmons. Nano Lett. 15, 4685–4691 (2015).
Babadjanyan, A. J., Margaryan, N. L. & Nerkararyan, K. V. Superfocusing of surface polaritons in the conical structure. J. Appl. Phys. 87, 3785–3788 (2000).
Becker, S. F. et al. Gap-plasmon-enhanced nanofocusing near-field microscopy. ACS Photonics 3, 223–232 (2016).
Genet, C., van Exter, M. P. & Woerdman, J. P. Fano-type interpretation of red shifts and red tails in hole array transmission spectra. Opt. Commun. 225, 331–336 (2003).
Ropers, C. et al. Femtosecond light transmission and subradiant damping in plasmonic crystals. Phys. Rev. Lett. 94, 113901 (2005).
Kollmann, H. et al. Fourier-transform spatial modulation spectroscopy of single gold nanorods. Nanophotonics 7, 715–726 (2018).
Purcell, E. M. Spontaneous emission probabilities at radio frequencies. Phys. Rev. 69, 681–681 (1946).
Gerard, J. M. et al. Enhanced spontaneous emission by quantum boxes in a monolithic optical microcavity. Phys. Rev. Lett. 81, 1110–1113 (1998).
Talebi, N. et al. Excitation of mesoscopic plasmonic tapers by relativistic electrons: phase matching versus eigenmode resonances. ACS Nano 9, 7641–7648 (2015).
Bouhelier, A., Beversluis, M., Hartschuh, A. & Novotny, L. Near-field second-harmonic generation induced by local field enhancement. Phys. Rev. Lett. 90, 013903 (2003).
Sönnichsen, C. et al. Drastic reduction of plasmon damping in gold nanorods. Phys. Rev. Lett. 88, 077402 (2002).
Novotny, L. Effective wavelength scaling for optical antennas. Phys. Rev. Lett. 98, 266802 (2007).
Esmann, M. et al. k-space imaging of the eigenmodes of sharp gold tapers for scanning near-field optical microscopy. Beilstein J. Nanotech. 4, 603–610 (2013).
Neuman, T. et al. Mapping the near fields of plasmonic nanoantennas by scattering-type scanning near-field optical microscopy. Laser Photon. Rev. 9, 637–649 (2015).
Berweger, S., Atkin, J. M., Xu, X. G., Olmon, R. L. & Raschke, M. B. Femtosecond nanofocusing with full optical waveform control. Nano Lett. 11, 4309–4313 (2011).
Sadiq, D. et al. Adiabatic nanofocusing scattering-type optical nanoscopy of individual gold nanoparticles. Nano Lett. 11, 1609–1613 (2011).
Piglosiewicz, B. et al. Carrier-envelope phase effects on the strong-field photoemission of electrons from metallic nanostructures. Nat. Photon. 8, 37–42 (2014).
The authors acknowledge financial support by the Deutsche Forschungsgemeinschaft (SPP1839 ‘Tailored Disorder’, grant LI 580/12 and SPP1840 ‘QUTIF’ grant LI 580/13), the Korea Foundation for International Cooperation of Science and Technology (Global Research Laboratory project, K20815000003) and the German–Israeli Foundation (GIF grant no. 1256 and 1074-49.10/2009). M.E. thanks the Studienstiftung des Deutschen Volkes (German Scholarship Foundation) for a PhD scholarship and the Deutsche Forschungsgemeinschaft (project 401390650). The authors thank V. Smirnov for performing supporting finite element method calculations and H. Kollmann for providing high-resolution SEM images of individual gold nanorods. The authors thank N. Talebi for discussions and supporting numerical calculations.
The authors declare no competing interests.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Esmann, M., Becker, S.F., Witt, J. et al. Vectorial near-field coupling. Nat. Nanotechnol. 14, 698–704 (2019). https://doi.org/10.1038/s41565-019-0441-y
Nature Photonics (2021)
Near-field transmission matrix microscopy for mapping high-order eigenmodes of subwavelength nanostructures
Nature Communications (2020)