Frequency Magnetically Tunable Terahertz Perfect Absorber Based on Graphene and Silica Layered Dielectric

Abstract

A frequency magnetically tunable perfect absorber based on graphene in the terahertz (THz) region is proposed. The performance is analysed using the 4 × 4 transfer matrix method, demonstrating that the perfect absorption frequency of the proposed absorber for a left-handed circularly polarized (LCP) wave can be dynamically tuned by varying the external static bias magnetic field in three frequency ranges (0.95–2.2 THz, 4.15–5.4 THz, and 7.3–8.55 THz). Due to the destructive interference of the reflected waves and the graphene-induced photonic band gap, the maximum absorption of the LCP wave can reach 99.91%. In addition, the proposed absorber can tolerate a wide range of incident angles for the LCP wave. This study may have great potential for various applications, such as detectors, sensors, and other optoelectronic devices in the THz region.