Abstract-Giant amplification of terahertz plasmons in a double-layer graphene

M Yu Morozov, I M Moiseenko,  V V Popov

https://iopscience.iop.org/article/10.1088/1361-648X/aaa648/meta

The amplification of terahertz plasmons in a pair of parallel active graphene monolayers is studied theoretically. The plasmon wave in a symmetric double-layer graphene structure splits into two branches with a symmetric and an antisymmetric distribution of tangential to graphene component of the electric field across the plane of symmetry of the structure. It is shown that, normalized to the wavelength, the terahertz plasmon amplification factor of the symmetric mode in the double-layer graphene structure could be greater than that in a single graphene layer by four orders of magnitude.

Abstract-Tunable Terahertz Deep Subwavelength Imaging Based on a Graphene Monolayer

• Heng-He Tang
• , Tie-Jun Huang
• , Jiang-Yu Liu
• , Yunhua Tan
•  & Pu-Kun Liu

https://www.nature.com/articles/srep46283

The resolution of conventional terahertz (THz) imaging techniques is limited to about half wavelength, which is not fine enough for applications of biomedical sensing and nondestructive testing. To improve the resolution, a new superlens, constructed by a monolayer graphene sheet combining with a grating voltage gate, are proposed in this paper to achieve deep super-resolution imaging in the THz frequency range. The main idea is based on the Fabry-Perot resonance of graphene edge plasmon waves. By shaping the voltage gate into a radial pattern, magnified images of subwavelength targets can be obtained. With this approach, the finest resolution can achieve up to λ/150. Besides, the superlens can be conveniently tuned to work in a large frequency band ranging from 4.3 THz to 9 THz. The proposal could find potential applications in THz near-field imaging systems.