title: Coupling-Enhanced Broadband Mid-infrared Light Absorption in Graphene Plasmonic Nanostructures.
abstract: Plasmons in graphene nanostructures show great promise for mid-infrared applications ranging from a few to tens of microns. However, mid-infrared plasmonic resonances in graphene nanostructures are usually weak and narrow-banded, limiting their potential in light manipulation and detection. Here, we investigate the coupling among graphene plasmonic nanostructures and further show that, by engineering the coupling, enhancement of light-graphene interaction strength and broadening of spectral width can be achieved simultaneously. Leveraging the concept of coupling, we demonstrate a hybrid two-layer graphene nanoribbon array which shows 5-7% extinction within the entire 8-14 μm (∼700-1250 cm-1) wavelength range, covering one of the important atmosphere "infrared transmission windows". Such coupled hybrid graphene plasmonic nanostructures may find applications in infrared sensing and free-space communications.
authors.affiliation: Department of Electrical Engineering, Yale University , New Haven, Connecticut 06511, United States.
authors.forename: Bingchen
authors.initials: B
authors.lastname: Deng
authors.affiliation: Department of Electrical Engineering, Yale University , New Haven, Connecticut 06511, United States.
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Department of Electrical Engineering, Yale University , New Haven, Connecticut 06511, United States.
authors.forename: Cheng
authors.initials: C
authors.lastname: Li
authors.forename: Haozhe
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Boston University , Boston, Massachusetts 02551, United States.
authors.forename: Xi
authors.initials: X
authors.lastname: Ling
authors.affiliation: IBM T.J. Watson Research Center , Yorktown Heights, New York 10598, United States.
authors.forename: Damon B
authors.initials: DB
authors.lastname: Farmer
authors.affiliation: IBM T.J. Watson Research Center , Yorktown Heights, New York 10598, United States.
authors.forename: Shu-Jen
authors.initials: SJ
authors.lastname: Han
authors.forename: Jing
authors.initials: J
authors.lastname: Kong
authors.affiliation: Department of Electrical Engineering, Yale University , New Haven, Connecticut 06511, United States.
authors.forename: Fengnian
authors.identifier: 0000-0001-5176-368X
authors.initials: F
authors.lastname: Xia
keywords: coupling; graphene; mid-infrared photonics; plasmon; spectroscopy