arXiv subjects

Saeedeh Barzegar-Parizi

Publications and source records attributed to Saeedeh Barzegar-Parizi.

3 recordsLinked to original sources

arXiv2019

High-Q Dual-Band Graphene Absorbers by Selective Excitation of Graphene Plasmon Polaritons: Circuit Model Analysis

This article presents the design of two dual-band graphene-based absorbers for terahertz frequencies. The absorbers are composed of two-dimensional (2D)arrays of ribbons and disks printed on a ground plane backed dielectric spacer. The design is based on the excitation of a specific plasmon polariton of the graphene patterned array at each resonance band. An analytical circuit model is used to derive closed-form relations for the geometrical parameters of the absorber and graphene parameters. The graphene patterned array appears as a surface admittance made of an infinite parallel array of series RLC branches. Each branch is equivalent to a graphene plasmon polariton (GPP) providing a distinct resonance mode. The design procedure is based on selectively exciting the first two GPPs. This means that two of the parallel RLC branches are selectively used in the circuit model analysis. The results obtained using the analytical solution are compared with the full-wave simulations in HFSS. The agreement between the results validates the developed design method.

physics.app-ph↗

arXiv2019

Designing Dual-Band Absorbers by Graphene/Metallic Metasurfaces

This article presents a novel approach for designing dual-band absorbers based on graphene and metallic metasurfaces for terahertz and mid-infrared regimes, respectively. The absorbers are composed of a two-dimensional (2D) array of square patches deposited on a dielectric film terminated by a metal plate. Using an analytical circuit model, we obtain closed-form relations for different parameters of the structure to achieve the dual-band absorber. Two absorption bands with obtained absorptivity of 98% at 0.55 and 1.54 THz for the graphene-based structure and 7 and 25 THz for the metallic-based case are achieved. We demonstrate that the graphene-based absorber remains as dual-band for a wide range of the Fermi level. Furthermore, the proposed dual-band absorbers have a polarization-insensitive characteristic remaining over a wide range of incident angles. The most important advantage of this device is its simplicity compared to previously reported structures.

physics.optics↗

arXiv2018

Graphene-based Tunable Dual-Band Absorbers by Ribbon/Disk Array

This article presents two dual-band absorbers based on graphene one dimensional (1D) / two dimensional (2D) patterned arrays in the THz frequencies. In comparison to the previous work, the structure of the proposed device is very simple. Most dual-band absorbers are based on mixing resonances of resonators with different sizes inside the structure. In this paper, the proposed absorber is based on the arrays of one element. Dual capacitive-inductive nature of the graphene patterned array and the impedance matching condition are used to achieve two resonance bands with perfect absorption by adjusting the graphene properties.

physics.optics↗