Permittivity-Asymmetric Quasi-Bound States in the Continuum of Localized Spoof Surface Plasmons
摘要
Quasi-bound states in the continuum (quasi-BICs) of localized spoof surface plasmons (LSSPs) have high quality factors (Q-factors) because of low radiation loss. In this paper, permittivity-asymmetric quasi-BICs of LSSPs are proposed. The unit cell of the metasurface contains a circular grating and two dielectric sheets. The quasi-BICs of the LSSPs are realized by breaking the symmetry of the permittivity of the dielectric sheets. This paper provides a new way to construct the quasi-BICs of the LSSPs.