Polarization Selective Multiple Fano Resonances in Coupled T-Shaped Metasurface

Abstract

The plasmonic responses of an array of coupled resonators are tailored to support multiple strong plasmonic Fano resonances at terahertz frequencies. The metasurface is formed by a periodic arrangement of T-shaped gold resonators. It is demonstrated that multiple Fano resonances can be achieved by breaking the symmetry of adjacent T-shaped resonators. Various configurations of the coupled T-shaped metasurface array are proposed, which support distinct multiple sharp Fano resonances with large modulation depths. Moreover, quality factors more than 130 are realized around Fano resonances, and an enhancement of the electric field exceeding 65 times around the hybridized modes is obtained. The highly dispersive polarization selective properties of the proposed coupled metasurface array are useful for various applications, including sensing, switching, and broadband slow-light devices.