Reconfigurable epsilon-near-zero metasurfaces via photonic doping

The next generation of flat optic devices aspires to a dynamic control of the wavefront characteristics. Here, we theoretically investigated the reconfigurable capabilities of an epsilon-near-zero (ENZ) metasurface augmented with resonant dielectric rods. We showed that the transmission spectrum of the metasurface is characterized by a Fano-like resonance, where the metasurface behavior changed from perfect magnetic conductor to epsilon-and-mu-near-zero material responses. The abrupt variation between these two extreme material responses suggests potential applications in dynamic metasurfaces. We highlighted the causality aspects of ENZ metasurfaces with a transient analysis and numerically investigated different reconfigurable mechanisms. Thus, this work introduces a new strategy for dynamic wavefront engineering.