Dark-state-based low-loss metasurfaces with simultaneous electric and magnetic resonant response

The realization of metamaterials or metasurfaces with simultaneous electric and magnetic response and low loss is generally very challenging at optical frequencies. Traditional approaches using nano-resonators made of noble metals, while suitable for the microwave and terahertz regimes, fail at frequencies above the near-infrared, due to prohibitive high dissipative losses and the breakdown of scaling resulting from the electron mass contribution (kinetic inductance) to the effective reactance of these plasmonic meta-atoms. The alternative route based on Mie resonances of high-index dielectric particles normally leads to structure sizes that tend to break the effective-medium approximation. Here, we propose a sub-wavelength dark-state-based metasurface, which enables configurable simultaneous electric and magnetic responses with low loss. Proof-of-concept metasurface samples, specifically designed around telecommunication wavelengths (i.e., λ~1.5 μm), were fabricated and investigated experimentally to val...