Abstract
We theoretically and experimentally investigate a metasurface supporting a silicon-slot quasi-bound state in the continuum (qBIC) mode resonating in the near-infrared spectrum. The metasurface is composed of circular slots etched in a silicon layer on a sapphire substrate. The symmetry of the metasurface unit cell is reduced in order to provide access to the symmetry-protected mode, whose properties are investigated by finite-element full-wave and eigenfrequency analysis. The measured transmittance spectra verify the excitation of the investigated qBIC mode with experimental quality factors exceeding 700. The near-field distribution of the resonant qBIC mode shows strong field confinement in the slots, leading to high sensitivity values for refractometry.
Original language | English |
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Article number | 109199 |
Journal | Optics and Laser Technology |
Volume | 161 |
Number of pages | 7 |
ISSN | 0030-3992 |
DOIs | |
Publication status | Published - 2023 |
Keywords
- Biosensing
- Bound states in the continuum
- Metamaterials
- Nanofabrication
- Silicon metasurfaces
- Symmetry-protected modes