Tunable broadband terahertz polarizer using graphene-metal hybrid metasurface

• Published in: Optics express Vol. 27; no. 23; pp. 33768 - 33778
• Main Authors: Meng, K, Park, S J, Li, L H, Bacon, D R, Chen, L, Chae, K, Park, J Y, Burnett, A D, Linfield, E H, Davies, A G, Cunningham, J E
• Format: Journal Article
• Language: English
• Published: United States 11.11.2019
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.27.033768

We demonstrate an electrically tunable polarizer for terahertz (THz) frequency electromagnetic waves formed from a hybrid graphene-metal metasurface. Broadband (>3 THz) polarization-dependent modulation of THz transmission is demonstrated as a function of the graphene conductivity for various wire grid geometries, each tuned by gating using an overlaid ion gel. We show a strong enhancement of modulation (up to ∼17 times) compared to graphene wire grids in the frequency range of 0.2-2.5 THz upon introduction of the metallic elements. Theoretical calculations, considering both plasmonic coupling and Drude absorption, are in good agreement with our experimental findings.