Terahertz Metamaterial Absorbers

AbstractTerahertz metamaterial absorbers (TMAs) can efficiently absorb electromagnetic wave in the range of 0.1–10 THz based on the tunable electromagnetic properties of artificially designed unit cells. TMAs can achieve perfect absorption, as well as broad band absorption. Specifically, TMAs can break the thickness limit of a device at a quarter wavelength, realizing ultra‐thin devices so as to facilitate integration with other systems. Accordingly, TMAs have high application value in communication, imaging, detection, security inspection, and other fields because of their characteristics of small size, perfect absorption, less restriction of natural materials, and tunable electromagnetic parameters. This review covers the fundamental principles and recent advances of TMAs, from the essential structural features of TMAs and working principle of various types of TMAs to the design and applications of corresponding structures, especially the TMAs that can be tuned by various approaches. The development trend and challenges of TMAs are briefly discussed too. It is envisioned that this review can help R&D of the future TMAs for real applications.