Graphene-enabled active terahertz focusing with wide tuning range. (9th July 2021)

• Record Type: Journal Article
• Authors: Huang, Jianzhou; Hu, Bin; Muhammad Ismail, Khan; Liu, Weiguang; Liu, Juan
• Is Part Of: Journal of physics. Volume 54:Number 38(2021)
• Publication Date: 2021-07-09
• Subjects: metamirror -- tunable focusing -- graphene -- terahertz; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/ac1008
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: Tunable terahertz (THz) metalenses using graphene have the advantages of good tunability, fast tuning speed, and ultra-small thickness for compact THz photonic systems. However, it is still a great challenge to realize such an active metalens with a large tuning range of focal length. Here, we propose a reflective metamirror with a graphene-coated metallic antenna array. Using an algorithm to find the C-shaped antennas with large phase changes when the graphene is gated, the metamirror with a wide tuning range is designed. The simulation results indicate that the focal length is able to be continuously changed by 96 λ when the graphene chemical potential increases from 0.04 eV to 0.52 eV at 1 THz. The full width at half maximum of the focus is close to the diffraction limit. This method is anticipated to open up a new way for designing graphene-based widely tunable THz metasurfaces.