Boosting Local Field Enhancement by on-Chip Nanofocusing and Impedance-Matched Plasmonic Antennas

Vladimir A. Zenin, Andrei Andryieuski, Radu Malureanu, Ilya P. Radko, Valentyn S. Volkov, Dmitri K. Gramotnev, Andrei Lavrinenko, Sergey I. Bozhevolnyi

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Abstract

Strongly confined surface plasmon-polariton modes can be used for efficiently delivering the electromagnetic energy to nanosized volumes by reducing the cross sections of propagating modes far beyond the diffraction limit, that is, by nanofocusing. This process results in significant local-field enhancement that can advantageously be exploited in modern optical nanotechnologies, including signal processing, biochemical sensing, imaging, and spectroscopy. Here, we propose, analyze, and experimentally demonstrate on-chip nanofocusing followed by impedance-matched nanowire antenna excitation in the end-fire geometry at telecom wavelengths. Numerical and experimental evidence of the efficient excitation of dipole and quadrupole (dark) antenna modes are provided, revealing underlying physical mechanisms and analogies with the operation of plane-wave Fabry-Pérot interferometers. The unique combination of efficient nanofocusing and nanoantenna resonant excitation realized in our experiments offers a major boost to the field intensity enhancement up to ∼12000, with the enhanced field being evenly distributed over the gap volume of 30 × 30 × 10 nm3, and promises thereby a variety of useful on-chip functionalities within sensing, nonlinear spectroscopy and signal processing.
Original languageEnglish
JournalNano letters
Volume15
Issue number12
Pages (from-to)8148-8154
ISSN1530-6984
DOIs
Publication statusPublished - 2015

Keywords

  • field enhancement
  • nanofocusing
  • optical antennas
  • phase-resolved near-field microscopy
  • Surface plasmons polaritons
  • tapered waveguide
  • Antennas
  • Diffraction
  • Electromagnetic wave polarization
  • Electromagnetic waves
  • Phonons
  • Photons
  • Plasmons
  • Quantum theory
  • Signal processing
  • Surface plasmon resonance
  • Field enhancement
  • Nano-focusing
  • Near field microscopy
  • Optical antennas
  • Tapered waveguide
  • Nanoantennas

Cite this

Zenin, V. A., Andryieuski, A., Malureanu, R., Radko, I. P., Volkov, V. S., Gramotnev, D. K., Lavrinenko, A., & Bozhevolnyi, S. I. (2015). Boosting Local Field Enhancement by on-Chip Nanofocusing and Impedance-Matched Plasmonic Antennas. Nano letters, 15(12), 8148-8154. https://doi.org/10.1021/acs.nanolett.5b03593