High-Contrast Terahertz Wave Modulation by Gated Graphene Enhanced by Extraordinary Transmission through Ring Apertures

• Published in: Nano letters Vol. 14; no. 3; pp. 1242 - 1248
• Main Authors: Gao, Weilu, Shu, Jie, Reichel, Kimberly, Nickel, Daniel V, He, Xiaowei, Shi, Gang, Vajtai, Robert, Ajayan, Pulickel M, Kono, Junichiro, Mittleman, Daniel M, Xu, Qianfan
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 12.03.2014
• Subjects: Apertures; Compatibility; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Graphene; High speed; Imaging; Materials science; Modulation; Modulators; Nanostructure; Physics; Specific materials; near-field enhancement; Graphene photonics; extraordinary optical transmission; high on/off ratio; THz modulator; THz range; Semiconductor materials; Graphene; Imaging; Apertures; Aperture; Gates
• ISSN: 1530-6984; 1530-6992; 1530-6992
• DOI: 10.1021/nl4041274

Gate-controllable transmission of terahertz (THz) radiation makes graphene a promising material for making high-speed THz wave modulators. However, to date, graphene-based THz modulators have exhibited only small on/off ratios due to small THz absorption in single-layer graphene. Here we demonstrate a ∼50% amplitude modulation of THz waves with gated single-layer graphene by the use of extraordinary transmission through metallic ring apertures placed right above the graphene layer. The extraordinary transmission induced ∼7 times near-filed enhancement of THz absorption in graphene. These results promise complementary metal–oxide–semiconductor compatible THz modulators with tailored operation frequencies, large on/off ratios, and high speeds, ideal for applications in THz communications, imaging, and sensing.