Full control over the propagation of light depends on our ability to independently, yet simultaneously, manipulate its electric and magnetic field components. Achieving this control at optical frequencies using metamaterials or metasurfaces with low loss is very challenging. Traditional approaches using nano-resonators made of noble metals, while suitable for the microwave and terahertz regimes, fail at frequencies above the near-infrared. 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. This work demonstrates a hybrid sub-wavelength dark-state-based metasurface which simultaneously enables configurable electric and magnetic responses with low loss. Metasurface samples, specifically designed around telecommunication wavelengths (1.5 μm), were fabricated and investigated experimentally to validate the theoretical concept. Because the electromagnetic field energy is localized and stored predominantly inside a dark resonant dielectric bound state, the proposed metasurfaces overcome the loss issue. This enables scaling to very high operation frequency without suffering from saturation of the resonance frequencies.
A. Jain, A.R. James, J. Nogan, T.S. Luk, G. Subramania, S. Liu, I. Brener, N. Shen, T. Koschny, and C.M. Soukoulis, Dark-state-based low-loss metasurfaces with simultaneous electric and magnetic resonant response , ACS Photonics 7, 241-248 (2020), https://doi.org/10.1021/acsphotonics.9b01480