METAMATERIAL ABSORBERS : REVIEW

Abstract

Metamaterials are man-made structures that exhibit extraordinary electromagnetic properties not typically found in natural materials. These unique materials hold great promise for a variety of advanced applications, one of the most prominent being metamaterial absorbers. The design of such absorbers relies on the simultaneous excitation of electric and magnetic dipole resonances. A standard metamaterial absorber consists of a three-layer structure: a top layer featuring metallic patterns at subwavelength scales, a metallic ground plane at the bottom, and a dielectric (insulating) layer sandwiched in between. The top patterned layer acts as an electric resonator, interacting with the electric field of incoming electromagnetic waves. Meanwhile, the magnetic response arises from the interplay between the two metallic layers and the intervening dielectric. To block wave transmission, the ground layer must be thicker than the skin depth. By adjusting the geometry of these structural components, one can tune the effective permittivity and permeability, allowing the structure to match the impedance of free space, which results in perfect absorption at specific wavelengths. In recent years, the need for chemical and biological sensing has driven the development of mid-infrared perfect metamaterial absorbers. This thesis focuses on literature review of various metamaterial absorbers and it’s other application.