Electrical access to critical coupling of circularly polarized waves in graphene chiral metamaterials

Teun-Teun Kim, Sang Soon Oh, Hyeon-Don Kim, Hyun Sung Park, Ortwin Hess, Bumki Min, Shuang Zhang

Research output: Contribution to journalArticlepeer-review

50 Citations (Scopus)
99 Downloads (Pure)

Abstract

Active control of polarization states of electromagnetic waves is highly desirable because of its diverse applications in information processing, telecommunications, and spectroscopy. However, despite the recent advances using artificial materials, most active polarization control schemes require optical stimuli necessitating complex optical setups. We experimentally demonstrate an alternative-direct electrical tuning of the polarization state of terahertz waves. Combining a chiral metamaterial with a gated single-layer sheet of graphene, we show that transmission of a terahertz wave with one circular polarization can be electrically controlled without affecting that of the other circular polarization, leading to large-intensity modulation depths (>99%) with a low gate voltage. This effective control of polarization is made possible by the full accessibility of three coupling regimes, that is, underdamped, critically damped, and overdamped regimes by electrical control of the graphene properties.

Original languageEnglish
Article numbere1701377
JournalScience Advances
Volume3
Issue number9
DOIs
Publication statusPublished - 29 Sep 2017

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