Research article

An ultrathin and flexible terahertz electromagnetically induced transparency-like metasurface based on asymmetric resonators

¹ School of Electronic Engineering and Computer Science, Queen Mary University of London, London E1 4FZ, UK
² James Watt School of Engineering, University of Glasgow, Glasgow, G12 8QQ, UK
³ School of Electronic Engineering and Computer Science, Queen Mary University of London, London E1 4FZ, UK

^* e-mail: s.nourinovin@qmul.ac.uk

Received: 18 November 2022
Accepted: 24 March 2023
Published online: 8 May 2023

Abstract

Terahertz (THz) electromagnetically induced transparency-like (EIT-like) metasurfaces have been extensively explored and frequently used for sensing, switching, slow light, and enhanced nonlinear effects. Reducing radiation and non-radiation losses in EIT-like systems contributes to increased electromagnetic (EM) field confinement, higher transmission peak magnitude, and Q-factor. This can be accomplished by the use of proper dielectric properties and engineering novel designs. Therefore, we fabricated a THz EIT-like metasurface based on asymmetric metallic resonators on an ultra-thin and flexible dielectric substrate. Because the quadruple mode is stimulated in a closed loop, an anti-parallel surface current forms, producing a transparency window with a transmission peak magnitude of 0.8 at 1.96 THz. To control the growing trend of EIT-like resonance, the structure was designed with four asymmetry levels. The effect of the substrate on the resonance response was also explored, and we demonstrated experimentally how the ultra-thin substrate and the metasurface asymmetric novel pattern contributed to higher transmission and lower loss.