Active broadband terahertz wave impedance matching based on optically doped graphene–silicon heterojunction. (28th February 2019)

• Record Type: Journal Article
• Authors: Du, Wanyi; Zhou, Yixuan; Yao, Zehan; Huang, Yuanyuan; He, Chuan; Zhang, Longhui; He, Yuhang; Zhu, Lipeng; Xu, Xinlong
• Is Part Of: Nanotechnology. Volume 30:Number 19(2019)
• Publication Date: 2019-02-28
• Subjects: graphene -- terahertz wave modulator -- impedance matching -- optical tunability -- heterojunction; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ab0329
• Languages: English
• ISSNs: 0957-4484

Abstract

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.