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

Weilu Gao , Jie Shu , Kimberly Reichel , Daniel V. Nickel , Xiaowei He , Gang Shi , Robert Vajtai ,Pulickel M Ajayan , Junichiro Kono , Daniel M. Mittleman , and Qianfan Xu

Nano Lett., Just Accepted Manuscript

DOI: 10.1021/nl4041274

Publication Date (Web): February 3, 2014

Copyright © 2014 American Chemical Society

http://pubs.acs.org/doi/abs/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 CMOS-compatible THz modulators with tailored operation frequencies, large on/off ratios, and high speeds, ideal for applications in THz communications, imaging, and sensing.