Abstract-Tunable Graphene-based Plasmonic Perfect Metamaterial Absorber in the THz Region

Zao Yi, , Jiajia Chen,  Chunlian Cen, Xifang Chen,  Zigang Zhou, Yongjian Tang, Xin Ye,  Shuyuan Xiao, Wei Lu,  Pinghui Wu,

file:///C:/Users/Randy/Downloads/micromachines-10-00194.pdf

The optical performance of a periodically tunable plasma perfect metamaterial absorber based on a square-square-circle array we propose in the terahertz region is analyzed in this work by the finite difference time domain (FDTD) method. We not only discuss the impact of various parameters such as period a, length L, radius R, and incident angle θ under transverse magnetic (TM)- and transverse electric (TE)-polarization on the absorption spectra of the absorber but also study the effect of the Fermi energy EF and relaxation time τ. Finally, we simulate the spectra as the surrounding refractive index n changes to better evaluate the sensing performance of the structure, producing a sensitivity S of the structure of up to 15006 nm/RIU. On account of this research, we find that the absorber is beneficial to sensors and detectors in the terahertz region.

Abstract-Plasmonic absorption characteristics based on dumbbell-shaped graphene metamaterial arrays

Chunlian Cen, Jiajia Chen, Hang Lin, Cuiping Liang, Jing Huang, Xifang Chen, Yongjian Tang, Zao Yi, Xibin Xu, Shuyuan Xiao

https://arxiv.org/abs/1802.10285

In this paper, we proposed a theoretical model in the far-infrared and terahertz (THz) bands, which is a dumbbell-shaped graphene metamaterial arrays with a combination of graphene nanorod and two semisphere-suspended heads. We report a detailed theoretical investigation on how to enhance localized electric field and the absorption in the dumbbell-shaped graphene metamaterial arrays. The simulation results show that by changing the geometrical parameters of the structure and the Fermi level of graphene, we can change the absorption characteristics. Furthermore, we have discovered that the resonant wavelength is insensitive to TM polarization. In addition, we also find that the double-layer graphene arrays have better absorption characteristics than single-layer graphene arrays. This work allows us to achieve tunable terahertz absorber, and may also provide potential applications in optical filter and biochemical sensing.