Dual plasmonically induced transparency and ultra-slow light effect in m-shaped graphene-based terahertz metasurfaces

Abstract

An m-shaped graphene-based metasurface is proposed, which can produce a dual dynamically tunable plasmonically induced transparency (PIT) by coupling among a dark mode and two bright modes. The numerical and theoretical results exhibit prominent consistency. The result shows that when the Fermi level of graphene is low, the graphene exhibits lossy dielectric; conversely, it behaves metallic properties. Moreover, the group delay can be as high as 0.6ps demonstrating the ultra-slow light effects. Thus, this study provides guidance for the design of multi-channel ultra-slow light and modulation devices in the terahertz range.