Design of a Tunable Ultra-Broadband Terahertz Absorber Based on Multiple Layers of Graphene Ribbons

Abstract

We propose and numerically demonstrate an ultra-broadband graphene-based metamaterial absorber, which consists of multi-layer graphene/dielectric on the SiO2 layer supported by a metal substrate. The simulated result shows that the proposed absorber can achieve a near-perfect absorption above 90% with a bandwidth of 4.8 Thz. Owing to the flexible tunability of graphene sheet, the state of the absorber can be switched from on (absorption > 90%) to off (reflection > 90%) in the frequencies range of 3–7.8 Thz by controlling the Fermi energy of graphene. Moreover, the absorber is insensitive to the incident angles. The broadband absorption can be maintained over 90% up to 50°. Importantly, the design is scalable to develop broader tunable terahertz absorbers by adding more graphene layers which may have wide applications in imaging, sensors, photodetectors, and modulators.

Graphene‐Based Materials toward Microwave and Terahertz Absorbing Stealth Technologies

“…Other kinds of structural designs have also been adopted for constructing terahertz absorbers . Hao and co‐workers experimentally demonstrated a transparent graphene terahertz absorber.…”

Metal and graphene hybrid metasurface designed ultra-wideband terahertz absorbers with polarization and incident angle insensitivity

“…Terahertz wave absorbers are capable of absorbing electromagnetic (EM) waves, and they have wide applications in imaging, sensors, photodetectors and modulators. [1][2][3][4][5] Therefore, terahertz absorber design is a hot topic in recent years. Traditional absorbers by engineering natural materials are widely researched in recent years.…”

“…In recent years, metamaterials/metasurfaces exhibit excellent characteristics in EM wave manipulation, 12,13 and they are widely applied in terahertz absorber design. [1][2][3]14 Metamaterial/ metasurface based absorbers can achieve perfect absorption thanks to the plasmonic resonances. 1,2 Metamaterials/metasurfaces are constructed by assembling subwavelength electrically/magnetically resonant particles, which allows us to tailor their permittivity and permeability.…”

Electrical Phase Control Based on Graphene Surface Plasmon Polaritons in Mid-infrared

“…Due to their tunability and small size, these graphene-based devices have advantages over traditional devices. In addition, graphene has been proven to support SPPs from a mid-infrared band to THz and SPPs bound to the surface of doped graphene, which exhibit a number of favorable properties [16,17]. The ability to fabricate large-sized, high-crystalline samples enables the lifetime of SPPs to reach hundreds of optical cycles, making graphene a potential alternative for precious metal SPPs [12].The phase modulation of light is at the core of many applications and much research [18].…”