1. Active broadband terahertz wave impedance matching based on optically doped graphene–silicon heterojunction
- Author
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Xinlong Xu, Chuan He, Yixuan Zhou, Wanyi Du, Yuanyuan Huang, Longhui Zhang, Zehan Yao, Yuhang He, and Lipeng Zhu
- Subjects
Materials science ,Terahertz radiation ,Impedance matching ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,Amplitude modulation ,law ,General Materials Science ,Wave impedance ,Electrical and Electronic Engineering ,business.industry ,Graphene ,Mechanical Engineering ,Doping ,Heterojunction ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Mechanics of Materials ,Reflection (physics) ,Optoelectronics ,0210 nano-technology ,business - Abstract
Broadband terahertz (THz) impedance matching is important for both spectral resolution improvement and THz anti-radar technology. Herein, graphene-silicon hybrid structure has been proposed for active broadband THz wave impedance matching with optical tunability. The main transmission pulse measured in the time domain indicates a modulation depth as high as 92.7% totally from the graphene-silicon interface. The interface reflection from the graphene-silicon junction implies that an impedance matching condition can be actively achieved by optical doping. To reveal the mechanism, we propose a graphene-silicon heterojunction model, which gives a full consideration of both the THz conductivity of graphene and the loss in doped junction layer. The theory fits well with the experimental results. This work proves active THz wave manipulation by junction effect and paves the way for active anti-reflection coating for THz components.
- Published
- 2019
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