@article{ffdf752176a84213be7142bac796b24b,
title = "Hyperpolarizability of plasmonic meta-atoms in metasurfaces",
abstract = "Plasmonic metasurfaces are promising as enablers of nanoscale nonlinear optics and flat nonlinear optical components. Nonlinear optical responses of such metasurfaces are determined by the nonlinear optical properties of individual plasmonic meta-atoms. Unfortunately, no simple methods exist to determine the nonlinear optical properties (hyperpolarizabilities) of the meta-atoms hindering the design of nonlinear metasurfaces. Here, we develop the equivalent RLC circuit (resistor, inductor, capacitor) model of such meta-atoms to estimate their second-order nonlinear optical properties, that is, the first-order hyperpolarizability in the optical spectral range. In parallel, we extract from second-harmonic generation experiments the first-order hyperpolarizabilities of individual meta-atoms consisting of asymmetrically shaped (elongated) plasmonic nanoprisms, verified with detailed calculations using both nonlinear hydrodynamic-FDTD and nonlinear scattering theory. All three approaches, analytical, experimental, and computational, yield results that agree very well. Our empirical RLC model can thus be used as a simple tool to enable an efficient design of nonlinear plasmonic metasurfaces.",
keywords = "Anharmonic RLC oscillator, Hyperpolarizability, Meta-atoms, Nonlinear Optics, Plasmonics",
author = "{Saad Bin-Alam}, M. and Joshua Baxter and Awan, {Kashif M.} and Antti Kiviniemi and Yaryna Mamchur and Lesina, {Antonio Cala} and Tsakmakidis, {Kosmas L.} and Huttunen, {Mikko J.} and Lora Ramunno and Ksenia Dolgaleva",
note = "Funding Information: The authors thank Robert W. Boyd, Ekaterina Poutrina, John E. Sipe, and Gerd Leuchs for their valuable feedback and suggestions. The authors also thank Martti Kauranen for providing his lab at Tampere University in Finland to perform the experiment. K.D. and L.R. acknowledge support from the Canada Research Chairs (CRC) Program. K.D. acknowledges the financial support of the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery program. M.S.B.-A. acknowledges the support of the Ontario Graduate Scholarship (OGS), the University of Ottawa Excellence Scholarship, and the University of Ottawa International Experience Scholarship. J.B. acknowledges the financial support of NSERC Canada Graduate Scholarship-Master{\textquoteright}s (CGSM) Program and the University of Ottawa Excellence Scholarship, and the computational resources of Compute Canada. M.J.H. acknowledges the support of the Academy of Finland (Grant 308596) and the Flagship of Photonics Research and Innovation (PREIN) funded by the Academy of Finland (Grant 320165). K.L.T. acknowledges support from the General Secretariat for Research and Technology(GSRT) and the Hellenic Foundation for Research and Innovation (HFRI) under Grant 1819. A.C.L. acknowledges the Bundesministerium f{\"u}r Buldung und Furschung (German Federal Ministry of Education and Research) under the Tenure-Track Programme, and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany{\textquoteright}s Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453). Publisher Copyright: {\textcopyright} XXXX American Chemical Society Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",
year = "2021",
doi = "10.1021/acs.nanolett.0c02991",
language = "English",
volume = "21",
pages = "51–59",
journal = "Nano Letters",
issn = "1530-6984",
publisher = "American Chemical Society",
number = "1",
}