Tunable Graphene-based Infrared Perfect Absorber for Sensing

In this paper, we proposed a perfect absorber composed of a periodic double-layer graphene ribbon arrays placed on a metallic reflector separated by a dielectric layer for infrared sensing. The anti-symmetric dipole-dipole coupling mode is excited as the impedance matching, resulting in a narrowband absorption spectrum. Numerical simulations show that the absorption and reflection properties of the absorber are sensitive to the refractive index of the surrounding medium. Furthermore, the plasmon resonance wavelength can be tuned by varying the Fermi energy level of graphene. Such a plasmonic absorber with high sensitivity can be beneficial for chemical and biosensor applications.