Graphene induced tunable and polarization-insensitive broadband metamaterial absorber

• Published in: Optics communications 2017-01, Vol.382, p.281-287
• Main Authors: Zhang, Yuping, Li, Yue, Cao, Yanyan, Liu, Yuanzhong, Zhang, Huiyun
• Format: Article
• Language: English
• Subjects: Broadband; Graphene; Metamaterial absorber; Tunable
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2016.08.003

We design a tunable and broadband metamaterial absorber in the mid-infrared region based on graphene. The unit cell of the proposed metamaterial absorber consists of circular gold patches, which coupled with a graphene layer, and are separated by a dielectric spacer from the gold film on the bottom. The absorption bandwidth is effectively extended by patterning multi-circular gold patches of different dimension elements with appropriate geometrical parameters in a co-plane. The metamaterial absorber achieves its frequency tunable characteristics via changing the applied voltage or chemical doping to manipulate graphene's Fermi energy. We analyzed the surface current distributions and the distributions of the z-component electric field for understanding the absorption mechanism. Moreover, the design principle here could be regarded as a template to extend bandwidth by introducing more circular patches into each unit cell. Our design has potential applications in various fields of stealth technology, photovoltaic devices, sensors, and broadband communication. •Graphene has attracted great interest worldwide due to its remarkable properties.•We design a broadband metamaterial absorber which is frequency tuned by graphene.•The proposed absorber can operate well with different polarization angles of incident waves.•Our results have potential applications in various fields of stealth, sensors, and communication.