Abstract-High-efficiency Huygens’ metasurface for terahertz wave manipulation

Ruiqiang Zhao, Zheng Zhu, Guohua Dong, Tingting Lv, Yuxiang Li, Chunying Guan, Jinhui Shi, and Han Zhang

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-44-14-3482

A fair amount of theoretical work has shown that Huygens’ metasurfaces well modulate electromagnetic waves by properly designing electrical impedance 𝑍𝑒𝑠$Z_{es}$ and magnetic admittance 𝑌𝑚𝑠$Y_{ms}$; however, the transmissive Huygens’ metasurface is still challenging in the terahertz band. In this work, a transmission-type Huygens’ metasurface with bilayer metallic patches has been proposed and theoretically demonstrated to show a reflectionless phase modulation for a linearly polarized terahertz wave. The simulation results show that the metasurface can achieve 2𝜋$2\pi$ phase coverage, and importantly the phase change can be simply achieved by changing a single geometric parameter of the metamolecule, along with a similar transmission effect. We design a high-efficiency beam deflector to realize an anomalous refraction with an angle of 19.8°. The proposed metasurface will provide a simple and direct way to realize efficient terahertz devices for wavefront manipulation.

© 2019 Optical Society of America

Abstract-THz Photonics in Two Dimensional Materials and Metamaterials: Properties, Devices and Prospects

Jinhui Shi,  Zhongjun Li,  David K. Sang,  Yuanjiang Xiang,  Jianqing Li,  Shuang Zhang,  Han Zhang

http://pubs.rsc.org/en/content/articlelanding/2018/tc/c7tc05460b#!divAbstract

Terahertz radiation refers to a broad electromagnetic spectrum range between microwave and infrared waves, which is also known as terahertz gap due to inadequate materials and technologies for its generation and manipulation. Atomically thin two dimensional (2D) materials such as graphene, black phosphorus (BP) and transition metal dichalcogenides (TMDs) provide a powerful platform for manipulating the propagation and detection of terahertz waves. Furthermore, hybrid meta-materials that feature the combination of artificially engineered meta-materials and 2D materials greatly facilitate dynamic modulation or manipulation of THz radiation towards novel terahertz applications. Herein, we review recent progress on 2D materials in the terahertz domain and hybrid metamaterials with engineered functionalities through the incorporation of graphene, TMDs and BPs. The emerging THz devices based on the modulation, nonlinearity, filtering, and Plasmonics of 2D Materials and Metamaterials will be highlighted, and a brief discussion with perspectives and the remaining challenges will be concluded.

Abstract-Asymmetric transmission of linearly polarized waves in terahertz chiral metamaterials

Shenying Fang1,a), Kang Luan2,a), Hui Feng Ma2, Wenjin Lv1, Yuxiang Li1,b), Zheng Zhu1, Chunying Guan1, Jinhui Shi1,3,b), and Tie Jun Cui

http://aip.scitation.org/doi/abs/10.1063/1.4974477

We experimentally demonstrate the asymmetric transmission of linearly polarized waves in a multilayer chiral metamaterial in the terahertz (THz) regime. The chiral metamaterial is constructed by two stacked orthogonal metallic layers embedded in polyimide dielectric layers. Simulated and measured results show that the proposed multilayer chiral metamaterial can achieve dual-band direction-dependent cross-polarization conversions for both x- and y-polarized THz waves. The polarized wave passing through the metamaterial will be converted into its orthogonal polarization state, while the same polarized wave is blocked along the reversed propagation direction. In addition, the asymmetric transmission band may be effectively engineered to other frequencies by slightly adjusting the gap width. We believe that our findings are beneficial in manipulating the polarization state of THz waves and exploring polarization-sensitive THz devices.