title: Independently tunable dual-band perfect absorber based on graphene at mid-infrared frequencies.
abstract: We design a dual-band absorber formed by combining two cross-shaped metallic resonators of different sizes within a super-unit-cell arranged in mirror symmetry. Simulations indicate that absorption efficiencies greater than 99% can be achieved at two different frequencies under normal incidence. We employ a design scheme with graphene integration, which allows independent tuning of individual absorption frequencies by electrostatically changing the Fermi energy of the graphene layer. High absorbance is maintained over a wide incident angle range up to 50 degrees for both TE and TM polarizations. It thus enables a promising way to design electrically tunable absorbers, which may contribute toward the realization of frequency selective detectors for sensing applications.
authors.affiliation: Qingdao Key Laboratory of Terahertz Technology, College of Electronic Communication and Physics, Shandong University of Science and Technology, Qingdao, Shandong 266510, China.|Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Qingdao Key Laboratory of Terahertz Technology, College of Electronic Communication and Physics, Shandong University of Science and Technology, Qingdao, Shandong 266510, China.
authors.forename: Tongtong
authors.initials: T
authors.lastname: Li
authors.affiliation: Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang, Sichuan 621999, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Qingdao Key Laboratory of Terahertz Technology, College of Electronic Communication and Physics, Shandong University of Science and Technology, Qingdao, Shandong 266510, China.
authors.forename: Huiyun
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: O'Hara
authors.affiliation: School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Ethan
authors.initials: E
authors.lastname: Abele
authors.affiliation: Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
authors.forename: Antoinette J
authors.initials: AJ
authors.lastname: Taylor
authors.affiliation: Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
authors.forename: Hou-Tong
authors.initials: HT
authors.lastname: Chen
authors.affiliation: Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
authors.forename: Abul K
authors.initials: AK
authors.lastname: Azad