Improving nanoscale terahertz field localization by means of sharply tapered resonant nanoantennas
Aglieri Vincenzo,
Jin Xin,
Rovere Andrea,
Piccoli Riccardo,
Caraffini Diego,
Tuccio Salvatore,
De Angelis Francesco,
Morandotti Roberto,
Macaluso Roberto,
Toma Andrea,
Razzari Luca
Affiliations
Aglieri Vincenzo
Institut National de la Recherche Scientifique – Énergie Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, Quebec, J3X 1S2, Canada
Jin Xin
Institut National de la Recherche Scientifique – Énergie Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, Quebec, J3X 1S2, Canada
Rovere Andrea
Institut National de la Recherche Scientifique – Énergie Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, Quebec, J3X 1S2, Canada
Piccoli Riccardo
Institut National de la Recherche Scientifique – Énergie Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, Quebec, J3X 1S2, Canada
Caraffini Diego
Institut National de la Recherche Scientifique – Énergie Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, Quebec, J3X 1S2, Canada
Tuccio Salvatore
Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy
De Angelis Francesco
Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy
Morandotti Roberto
Institut National de la Recherche Scientifique – Énergie Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, Quebec, J3X 1S2, Canada
Macaluso Roberto
Università degli Studi di Palermo – Dipartimento di Ingegneria, Viale delle Scienze, 90128,Palermo, Italy
Toma Andrea
Clean Room Facility, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genova, Italy
Razzari Luca
Institut National de la Recherche Scientifique – Énergie Matériaux et Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, Quebec, J3X 1S2, Canada
Terahertz resonant nanoantennas have recently become a key tool to investigate otherwise inaccessible interactions of such long-wavelength radiation with nano-matter. Because of their high-aspect-ratio rod-shaped geometry, resonant nanoantennas suffer from severe loss, which ultimately limits their field localization performance. Here we show, via a quasi-analytical model, numerical simulations, and experimental evidence, that a proper tapering of such nanostructures relaxes their overall loss, leading to an augmented local field enhancement and a significantly reduced resonator mode volume. Our findings, which can also be extended to more complex geometries and higher frequencies, have profound implications for enhanced sensing and spectroscopy of nano-objects, as well as for designing more effective platforms for nanoscale long-wavelength cavity quantum electrodynamics.
