The "artificial magnetic" resonance in plasmonic metamolecules extends the potential application of magnetic resonance from terahertz to optical frequency bypassing the problem of magnetic response saturation by replacing the conduction current with the ring displacement current. So far, the magnetic Fano resonance-induced nonlinearity enhancement in plasmonic metamolecule rings has not been reported. Here, we use the magnetic Fano resonance to enhance second-harmonic generation (SHG) in plasmonic metamolecule rings. In the spectra of the plasmonic metamolecule, an obvious Fano dip appears in the scattering cross section, while the dip does not appear in the absorption cross section. It indicates that at the Fano dip the radiative losses are suppressed, while the optical absorption efficiency is at a high level. The largely enhanced SHG signal is observed as the excitation wavelength is adjusted at the magnetic Fano dip of the plasmonic metamolecule rings with stable and tunable magnetic responses. We also compare the magnetic Fano dip with the electric case to show its advantages in enhancing the fundamental and second harmonic responses. Our research provides a new thought for enhancing optical nonlinear processes by magnetic modes.
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http://dx.doi.org/10.1039/c7nr00587c | DOI Listing |
Sci Rep
January 2025
Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef, 62512, Egypt.
This paper presents a novel investigation of a magnetic sensor that employs Fano/Tamm resonance within the photonic band gap of a one-dimensional crystal structure. The design incorporates a thin layer of gold (Au) alongside a periodic arrangement of Tantalum pentoxide ([Formula: see text]) and Cesium iodide ([Formula: see text]) in the configuration [Formula: see text]. We utilized the transfer matrix method in conjunction with the Drude model to analyze the formation of Fano/Tamm states and the permittivity of the metallic layer, respectively.
View Article and Find Full Text PDFThe increasing demand for controlling electromagnetic waves has led to the construction of a variety of metasurface absorbers with different functionalities. In this Letter, we designed a kind of single-layer metasurfaces with delicately designed hybrid magnetic meta-atoms (HMMAs), which can be operated as perfect absorbers (PAs) for the electromagnetic wave incident at a specified direction, but at the mirror symmetric direction, the nearly total reflection is achieved. This remarkable nonreciprocal phenomenon arises from the time-reversal symmetry (TRS) breaking nature of magnetic surface plasmon as well as the lattice Kerker effect due to the interaction of HMMAs in the single-layer metasurfaces.
View Article and Find Full Text PDFNanophotonics
February 2024
Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, Jinlin 130033, China.
The metasurface refractive index sensor has a high degree of tunability and flexibility, providing excellent performance for high precision refractive index sensing applications. The metasurface absorber with metallic structure has been hindered in further sensor applications due to the inherent Ohmic loss of the metallic material. In this study, a dual nanorod metasurface structure based on semiconductor Si was designed, introducing a symmetry-breaking structure to excite dual ultra-narrow q-BIC resonance peaks with Fano line shapes.
View Article and Find Full Text PDFNanophotonics
July 2024
Institute of Electro-Optical Engineering, National Taiwan Normal University, Taipei 11677, Taiwan.
We develop a new all-dielectric metasurface for designing high quality-factor (-factor) quasi-bound states in the continuum (quasi-BICs) using asymmetry kite-shaped nanopillar arrays. The -factors of quasi-BICs follow the quadratic dependence on the geometry asymmetry, and meanwhile their resonant spectral profiles can be readily tuned between Fano and Lorentzian lineshapes through the interplay with the broadband magnetic dipole mode. The third-harmonic signals of quasi-BIC modes exhibit a gain from 43.
View Article and Find Full Text PDFNano Lett
December 2024
Institut für Physik, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.
Semiconducting halide perovskite nanoparticles support Mie-type resonances that confine light on the nanoscale in localized modes with well-defined spatial field profiles yet unknown near-field dynamics. We introduce an interferometric scattering-type near-field microscopy technique to probe the local electric field dynamics at the surface of a single MAPbI nanoparticle. The amplitude and phase of the coherent light scattering from such modes are probed in a broad spectral range and with high spatial resolution.
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