Rich Near-Infrared Chiral Behavior in Diffractive Metasurfaces
| Autor: | Tiziana Cesca, Giovanni Mattei, Emilija Petronijevic, Alessandro Belardini, Concetta Sibilia, Carlo Scian |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
business.industry High Energy Physics::Lattice Near-infrared spectroscopy metamaterials plasmonics photonics Physics::Optics General Physics and Astronomy Electric dipole moment Wavelength Extinction (optical mineralogy) Nanosphere lithography Optoelectronics Chirality (chemistry) business Refractive index Nanoscopic scale |
| Popis: | The mimicking of chiral effects at the nanoscale usually requires complex nanostructured systems fabricated by using highly sophisticated techniques. Here, we demonstrate that low-cost diffractive metasurfaces, fabricated by nanosphere lithography, can offer a remarkably rich chiral broadband response in the near-infrared range. We measure the spin-dependent response as a function of the incident angle and wavelength. The resulting extinction maps reveal switching of the resonances governed by extrinsic chirality. We further employ numerical modeling to gain an insight into the electromagnetic behavior over the unit cell. The simulation results agree with experiments, and we further investigate the possibility of tailoring chirality by matching the refractive index below and above the metasurface. Finally, we investigate chiral emission of the ensemble of electric dipoles embedded in the refractive-index-matching layer. This approach opens alternative perspectives for chiral surface-lattice resonances and chiral emission in low-cost materials. |
| Databáze: | OpenAIRE |
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