Terahertz Beam Steering Technologies: From Phased Arrays to Field‐Programmable Metasurfaces

In past decades, terahertz radiation, which locates between microwave and far‐infrared light in the electromagnetic spectrum, has attracted more and more attention. Various passive and active components such as absorbers, filters, polarizers, and focusing lenses have been developed for manipulating terahertz radiation. With the further evolution of metamaterials and metasurfaces, unprecedented freedom is gained for flexibly controlling terahertz...