1. Dual-wavelength chiral metasurfaces based on quasi-bound states in the continuum
- Author
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Run Chen, Qianhui Bi, Tianyue Li, Shuming Wang, Shining Zhu, and Zhenlin Wang
- Subjects
Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Abstract
In this paper, we numerically demonstrate a dual-wavelength chiral metasurface with the chirality only existing at two resonant wavelengths, making use of the excitation of two quasi-bound states in the continuum (quasi-BICs). This chiral metasurface is constructed on the basis of photonic crystal slabs with square lattice of circular holes by introducing rectangular holes as perturbations. The two quasi-BICs supported by chiral metasurface are orthogonal to each other, thus the chirality at the two resonant wavelengths can be controlled independently by changing the geometry of the perturbations. Furthermore, a chirality-switchable metasurface is demonstrated taking advantage of the sensitivity of quasi-BICs to the variation of out-of-plane symmetry caused by changing refractive index of surroundings. The proposed chiral metasurface could find potential applications in nonlinear optics, sensing, imaging and near-to-eye displays.
- Published
- 2023