Dual-layer metallic wire-hole structures were fabricated and their terahertz transmission properties were measured. They exhibit polarization-dependent transmittance with large extinction ratios. Simulation and experimental results on structures with different wire-to-hole orientations provide strong evidence that the resonance peaks are caused by plasmonic coupling between the two metallic layers. A simplified LC-circuit model is proposed to explain the coupling mechanism and to estimate the peak frequencies. Our results suggest that specific electromagnetic response can be achieved by appropriate design of the geometrical patterns on the two metallic layers and a suitable polarization of the incident wave.
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http://dx.doi.org/10.1364/OE.19.002791 | DOI Listing |
J Phys Chem Lett
January 2025
Department of Nature and Environment, Faculty of Liberal Arts, The Open University of Japan, Chiba 261-8586, Japan.
In this work, we study the plexciton in the far-ultraviolet region formed between indium nanoclusters and water molecules. The indium clusters are fabricated on graphene under ultrahigh vacuum conditions and show a strong localized surface plasmon polariton (LSP) absorption band at 6-7 eV. Adsorption of water molecules onto the clusters at 115 K induces a band splitting larger than 1 eV, indicating a strong coupling between the LSP and water 4a ← 1b transition.
View Article and Find Full Text PDFSmall
January 2025
CNR NANOTEC Institute of Nanotechnology, Via Monteroni, 73100, Lecce, Italy.
Photonics bound states in the continuum (BICs) are peculiar localized states in the continuum of free-space waves, unaffected by far-field radiation loss. Although plasmonic nano-antennas squeeze the optical field to nanoscale volumes, engineering the emergence of quasi-BICs with plasmonic hotspots remains challenging. Here, the origin of symmetry-protected (SP) quasi-BICs in a 2D system of silver-filled dimers, quasi-embedded in a high-index dielectric waveguide, is investigated through the strong coupling between photonic and plasmonic modes.
View Article and Find Full Text PDFSci Rep
January 2025
Faculty of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, Chuo-ku, Kobe, 650-0047, Hyogo, Japan.
Environmental pollution caused by heavy metals are problems worldwide. In particular, pollution and poisoning by lead ions (Pb) continue to be common and serious problems. Hence, there is a need for a widely usable method to easily detect Pb from solutions containing organic materials from environmental water such as seas, ponds, etc.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 Xianning West Road, Xi'an, 710049, China. Electronic address:
Background: Plasmonic core-shell nanostructures with embedded internal markers used as Raman probes have attracted great attention in surface-enhanced Raman scattering (SERS) immunoassay for cancer biomarkers due to their excellent uniform enhancement. However, current core-shell nanostructures typically exhibit a spherical shape and are coated with a gold shell, resulting in constrained local field enhancement.
Results: In this work, we prepared a core-shell AuNR@BDT@Ag structure by depositing silver on the surface of Raman reporter-modified gold nanorods (AuNR).
Sci Rep
January 2025
Department of Electrical and Computer Engineering, Tarbiat Modares University, Tehran, 14115-194, Iran.
With the increasing global attention to deep learning and the advancements made in applying convolutional neural networks in electromagnetics, we have recently witnessed the utilization of deep learning-based networks for predicting the spectrum and electromagnetic properties of structures instead of traditional tools like fully numerical-based methods. In this study, a Convolutional Neural Network (CNN is proposed for predicting spoof surface plasmon polaritons, enabling the examination of the absorption spectrum of metallic multilevel-grating structures (MMGS) and designing various sensor devices and absorbers in the shortest time possible. To expedite the training process of this network, a semi-analytical method of rigorous coupled-wave analysis (RCWA) enhanced with the fast Fourier factorization (FFF) technique has been employed, significantly reducing the data generation time for training.
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