Run Chen,Qianhui Bi,Tianyue Li,Shuming Wang,Shining Zhu,Zhenlin Wang
出处
期刊:Journal of Optics [IOP Publishing] 日期:2023-02-15卷期号:25 (4): 045001-045001被引量:9
标识
DOI:10.1088/2040-8986/acbc32
摘要
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.