Efficient flat metasurface lens for terahertz imaging.
Metamaterials offer exciting opportunities that enable precise control of amplitude, polarization and phase of the light beam at a subwavelength scale. A gradient metasurface consists of a class of anisotropic subwavelength metamaterial resonators that offer abrupt amplitude and phase changes, thus enabling new applications in optical device design such as ultrathin flat lenses. We propose a highly efficient gradient metasurface lens based on a metal-dielectric-metal structure that operates in the terahertz regime. The proposed structure consists of slotted metallic resonator arrays on two sides of a thin dielectric spacer. By varying the geometrical parameters, the metasurface lens efficiently manipulates the spatial distribution of the terahertz field and focuses the beam to a spot size on the order of a wavelength. The proposed flat metasurface lens design is polarization insensitive and works efficiently even at wide angles of incidence.
Quanlong
Q
Yang
Jianqiang
J
Gu
Dongyang
D
Wang
Xueqian
X
Zhang
Zhen
Z
Tian
Chunmei
C
Ouyang
Ranjan
R
Singh
Jiaguang
J
Han
Weili
W
Zhang
D003198:Computer Simulation; D004560:Electricity; D004867:Equipment Design; D007909:Lenses; D008962:Models, Theoretical; D055069:Terahertz Imaging