Dual‐Band Terahertz Metamaterial Absorber Based on LC Resonance and Dipolar Response and Its Applications

Abstract

AbstractThis study presents a new dual‐band terahertz absorber (DBTA) with ease of production consisting of a metallic base plane of a certain thickness, a dielectric layer on this plane, and a hexagonal metallic metasurface structure. The proposed absorber exhibits absorption band peaks above 99% at two distinct frequencies (7.51 and 8.08 THz). The absorption origin is explained as a dual‐band response using the LC resonance and dipolar response. In this way, the presented absorber facilitates production by improving absorption responses with a much simpler structure, unlike studies with complex geometries. The proposed dual‐band absorber results in sensitivity to the polarization of the incident light. Thus, it also makes the proposed structure very helpful for manipulating wave polarization and detecting waves with particular polarization. The hexagonal structure of the absorber is scaled to millimeter dimensions, and its transformation into another dual‐band absorber that can also operate in microwave frequency regions. Similarly, the hexagonal structure is transformed into a circular structure with the same geometric dimensions, and a different dual‐band absorber is obtained in the terahertz (THz) region. Moreover, the proposed concept can be extended for various applications such as bolometric sensing, thermal imaging, energy harvesting, sensing, and selective thermal emitters.