Abstract-Polarization-dependent electromagnetic responses of ultrathin and highly flexible asymmetric terahertz metasurfaces

Joshua A. Burrow, Riad Yahiaoui, Andrew Sarangan, Imad Agha, Jay Mathews, Thomas A. Searles

(Submitted on 18 Oct 2017)

https://arxiv.org/abs/1710.06714

We report the polarization-dependent electromagnetic response from a series of novel terahertz (THz) metasurfaces where asymmetry is introduced through the displacement of two adjacent metallic arms separated by a distance δ. For all polarization states, the symmetric metasurface exhibits a low quality (Q) factor fundamental dipole mode. By breaking the symmetry, we experimentally observe a secondary dipole-like mode with a Q factor nearly 9× higher than the fundamental resonance. As δ increases, the fundamental dipole mode f1 redshifts and the secondary mode f2 blueshifts creating a highly transmissive spectral window. Polarization-dependent measurements reveal a full suppression of f2 for all asymmetries at θ≥60∘. Furthermore, at δ≥60 μm, we observe a polarization selective electromagnetic induced transparency (EIT) for the fundamental mode. This work paves the way for applications in filtering, sensing and slow-light devices common to other high Q factor THz metasurfaces with EIT-like response.