Observation of electromagnetically induced absorption in a three-resonator system

Classic analog of the electromagnetically induced transparency (EIT) in metamaterials has been demonstrated extensively by its attractive potential applications in light storage, slow light and sensing. However, the counterpart of EIT, electromagnetically induced absorption (EIA) has been studied rarely in coupled metamaterial systems. Here, we present the observation of the EIA effect in a vertically coupled three-resonator metamaterial. A well-defined absorption resonance is developed in the EIT window enabling a unique double-peak transparency, due to the magnetic resonance induced by the near-field coupling of the three resonators. The analog of EIA opens up a new route to advanced photonics devices.