Broadband terahertz modulator based on graphene metamaterials

Zehua Huang,Yadong Jiang,Jun Wang,Qi Han,Chunhui Ji

doi:10.1063/1.5018261

Abstract

Tunable complementary split ring resonators (CSRRs) based on monolayer graphene are presented in terahertz regime. By applying different gate voltage, the Fermi level and optical conductivity of monolayer graphene pattern can be changed. Here, we employ a numerical simulation to study the interaction of light with graphene CSRRs. The results indicate that the extinction in transmission becomes stronger, and the resonance frequency presents blue shift with higher Fermi level of the graphene pattern. Three pronounced resonant peaks appear which can be modulated dynamically in the range of 1-2THz and 3-7THz, and realizing dynamic broadband terahertz modulation, the modulation depth exceeds 85% at all three resonant peaks, the highest modulation depth reaches 98.8% at 7.47THz.

Highlights

Graphene is a one-atom-thick two-dimensional material discovered in 2004.1 The conductivity of graphene can be modulated from terahertz (THz) to near-infrared (NIR) frequencies.[2]
Ri and Ro represent the radius of the inner circle and the outer circle of the graphene complementary split ring resonators (CSRRs), Px and Py are the period lengths along the x and y directions respectively
When the incident light interacts with the graphene CSRR, LC resonance occurs in low frequency, and two dipolar mode resonant peaks in high frequency can be confirmed through the field distributions

Summary

Broadband terahertz modulator based on graphene metamaterials

Cite as: AIP Advances 8, 035304 (2018); https://doi.org/10.1063/1.5018261 Submitted: 05 December 2017 • Accepted: 25 February 2018 • Published Online: 06 March 2018 ARTICLES YOU MAY BE INTERESTED IN Broadband graphene-based metamaterial absorbers AIP Advances 8, 015301 (2018); https://doi.org/10.1063/1.4998321 Graphene-based tunable metamaterial terahertz filters Applied Physics Letters 105, 093105 (2014); https://doi.org/10.1063/1.4894807 Dyadic Green’s functions and guided surface waves for a surface conductivity model of graphene Journal of Applied Physics 103, 064302 (2008); https://doi.org/10.1063/1.2891452 Zehua Huang, Qi Han, Chunhui Ji, Jun Wang,a and Yadong Jiang School of Optoelectronic Information, State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, PR China (Received 5 December 2017; accepted 25 February 2018; published online 6 March 2018)

INTRODUCTION

SIMULATION RESULTS AND DISCUSSION

CONCLUSIONS