Diffuse THz Scattering via Coding Metasurfaces

The Terahertz region covers the electromagnetic spectrum incorporating the advantages of both microwaves and infrared light waves. Many different techniques have been proposed to manipulate THz waves. Among them, metamaterials and metasurfaces have proven to have a high potential to engineer new type of functional THz devices. A recent and promising approach is based on coding metasurfaces, consisting of two or more basic ("digital") unit cells with out-of-phase response, which can be used to achieve diffuse scattering. Here, with special focus on the scattering-signature reduction, the physical mechanism is elucidated via a theoretical study and the relevant scaling-laws validated using THz Time Domain Spectroscopy.