Graphene-based active metasurface with more than 330° phase tunability operating at mid-infrared spectrum

Zhanshan Sun, Fumin Huang, Yunqi Fu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Metasurfaces composed of subwavelength optical antennas offer fruitful functionalities to manipulate the amplitude, phase and polarization of light. Sufficient phase tunability of metasurfaces has significant potential for dynamic beam steering, hologram and flat optics exhibiting tunable focusing. Here, we demonstrate a graphene based metasurface that gives rise to more than 330° smooth and continuous phase modulation at mid-infrared spectrum. The phase modulator model introduces multiple resonances including Split-Ring-resonator (SRR) resonance and inductance-capacitance (LC) resonance, leading to the outstanding sensitivity of the metasurface to tiny change of surrounding electromagnetic environment. Through adjusting the Fermi level of the monolayer graphene beneath the resonators, both scattered amplitude and phase can be efficiently modulated, so that the electrically programmable metasurface enables nearly arbitrary manipulation of scattered wavefront. Electro-optically tunable focusing and beam steering are numerally realized by constructing one dimensional discrete array element. The phased array design achieves an average efficiency up to 22% within 60° steering range. The reflective focusing lens with focal lengths of 10 μm, 15 μm and 20 μm are successfully demonstrated, respectively. The proposed metasurface has promising potential in optoelectronic applications such as imaging, sensing and focusing.

Original languageEnglish
Pages (from-to)512-520
Number of pages9
JournalCarbon
Volume173
Early online date19 Nov 2020
DOIs
Publication statusPublished - Mar 2021

Bibliographical note

Funding Information:
This research was funded by National Natural Science Foundation of China (NSFC) ( 61901492 ), ( 61901493 ) and the China Scholarship Council (CSC) .

Publisher Copyright:
© 2020 Elsevier Ltd

Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.

Keywords

  • Beam steering
  • Focusing
  • Graphene
  • Metasurface
  • Phase modulation

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)

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