| Autor: |
Qiushi Li, Xiaodong Cai, Tong Liu, Min Jia, Qiong Wu, Haoyang Zhou, Huanhuan Liu, Qianqian Wang, Xiaohui Ling, Cong Chen, Fan Ding, Qiong He, Yuanbo Zhang, Shiyi Xiao, Lei Zhou |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
Nanophotonics. 11:2085-2096 |
| ISSN: |
2192-8614 |
| Popis: |
Dynamical controls on terahertz (THz) wavefronts are crucial for many applications, but available mechanism requests tunable elements with sub-micrometer sizes that are difficult to find in the THz regime. Here, different from the local-tuning mechanism, we propose an alternative approach to construct wavefront-control meta-devices combining specifically designed metasurfaces and globally tuned graphene layers. Coupled-mode-theory (CMT) analyses reveal that graphene serves as a tunable loss to drive the whole meta-device to transit from one functional phase to another passing through an intermediate regime, exhibiting distinct far-field (FF) reflection wavefronts. As a proof of concept, we design/fabricate a graphene meta-device and experimentally demonstrate that it can reflect normally incident THz wave to pre-designed directions with different polarizations under appropriate gating voltages. We finally design a graphene meta-device and numerically demonstrate that it can generate vectorial THz beams with continuously varying polarization distributions upon gating. These findings pave the road to realizing a wide range of THz applications, such as sensing, imaging, and wireless communications. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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