Unveiling the Symmetry Protection of Bound States in the Continuum with Terahertz Near-Field Imaging
| Autor: | Stan ter Huurne, Francesco Verdelli, Jaime Gómez Rivas, Niels van Hoof, Giel C.A. Timmermans, Diego R. Abujetas, José A. Sánchez-Gil |
|---|---|
| Přispěvatelé: | Surface Photonics, Photonics and Semiconductor Nanophysics, Center for Terahertz Science and Technology Eindhoven, Applied Physics and Science Education, ICMS Core, Research Foundation - Flanders, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Educación, Cultura y Deporte (España) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Electromagnetic field
Physics THz time-domain spectroscopy Terahertz radiation metasurfaces Atomic and Molecular Physics and Optics Symmetry (physics) Article Electronic Optical and Magnetic Materials Computational physics Metasurfaces Amplitude THz near-field microscopy Bound state Symmetry-protected bound states in the continuum Electrical and Electronic Engineering coupled dipole model Mirror symmetry Local field Coupled dipole model Excitation Biotechnology |
| Zdroj: | ACS Photonics, 8(10), 3010-3016. American Chemical Society ACS Photonics, 8, 3010-3016 ACS Photonics Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 2330-4022 |
| Popis: | 7 pags., 7 figs. Bound states in the continuum (BICs) represent a new paradigm in photonics due to the full suppression of radiation losses. However, this suppression has also hampered the direct observation of them. By using a double terahertz (THz) near-field technique that allows the local excitation and detection of the THz amplitude, we are able to map for the first time the electromagnetic field amplitude and phase of BICs over extended areas, unveiling the field-symmetry protection that suppresses the far-field radiation. This investigation, done for metasurfaces of dimer scatterers, reveals the in-plane extension and formation of BICs with antisymmetric phases, in agreement with coupled-dipole calculations. By displacing the scatterers, we show experimentally that a mirror symmetry is not a necessary condition for a BIC formation. Only π-rotation symmetry is required, making BICs exceptionally robust to structural changes. This work makes the local field of BICs experimentally accessible, which is crucial for the engineering of cavities with infinite lifetimes. The authors thank K. de Mare for help in the development of the setup and Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) (Vici 680-47-628); Spanish Ministerio de Ciencia e Innovación (MICIU/AEI/FEDER, UE) through the grants MELODIA (PGC2018-095777−B-C21) and NANOTOPO (FIS2017-91413-EXP), and Ministerio de Educación, Cultura y Deporte through a PhD Fellowship (FPU15/03566) for funding. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|