Monolayer-Graphene-Based Tunable Absorber in the Near-Infrared

In this paper, a tunable absorber composed of asymmetric grating based on a graphene-dielectric-metal structure is proposed. The absorption of the absorber can be modified from 99.99% to 61.73% in the near-infrared by varying the Fermi energy of graphene, and the absorption wavelength can be tuned by varying the grating period. Furthermore, the influence of other geometrical parameters, the incident angle, and polarization are analyzed in detail by a finite-difference time-domain simulation. The graphene absorbers proposed in this paper have potential applications in the fields of stealth, sense, and photoelectric conversion. When the absorber that we propose is used as a gas sensor, the sensitivity of 200 nm/RIU with FOM can reach up to 159 RIU-1.

Automated summary

This paper presents a tunable absorber based on an asymmetric grating composed of a graphene-dielectric-metal structure, with the absorption rate and wavelength in the near-infrared region adjustable by varying the Fermi energy of graphene and grating period. The influence of other geometrical parameters, incident angle, and polarization is analyzed through simulation. The proposed absorbers have potential applications as gas sensors, with a sensitivity of 200 nm/RIU and FOM up to 159 RIU-1.