TY - JOUR
T1 - Boosting Local Field Enhancement by on-Chip Nanofocusing and Impedance-Matched Plasmonic Antennas
AU - Zenin, Volodymyr
AU - Andryieuski, Andrei
AU - Malureanu, Radu
AU - Radko, Ilya
AU - Volkov, Valentyn S.
AU - Gramotnev, Dmitri K.
AU - Lavrinenko, Andrei V.
AU - Bozhevolnyi, Sergey I.
PY - 2015/11/9
Y1 - 2015/11/9
N2 - Strongly confined surface plasmon-polariton modes can be used for efficiently delivering the electromagnetic energy to nano-sized volumes by reducing the cross sections of propagating modes far beyond the diffraction limit, i.e., 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 evidences 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.
AB - Strongly confined surface plasmon-polariton modes can be used for efficiently delivering the electromagnetic energy to nano-sized volumes by reducing the cross sections of propagating modes far beyond the diffraction limit, i.e., 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 evidences 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.
KW - Surface plasmons polaritons
KW - phase-resolved near-field microscopy
KW - optical antennas
KW - field enhancement
KW - tapered waveguide
KW - nanofocusing
U2 - 10.1021/acs.nanolett.5b03593
DO - 10.1021/acs.nanolett.5b03593
M3 - Journal article
C2 - 26551324
VL - 15
SP - 8148
EP - 8154
JO - Nano Letters
JF - Nano Letters
SN - 1530-6984
IS - 12
ER -