Abstract-Terahertz dual-band metamaterial absorber based on graphene/MgF2 multilayer structures

Zhaoxian Su, Jianbo Yin, and Xiaopeng Zhao

http://65.202.222.105/oe/abstract.cfm?uri=oe-23-2-1679

We design an ultra-thin terahertz metamaterial absorber based on graphene/MgF2 multilayer stacking unit cells arrayed on an Au film plane and theoretically demonstrate a dual-band total absorption effect. Due to strong anisotropic permittivity, the graphene/MgF2 multilayer unit cells possess a hyperbolic dispersion. The strong electric and magnetic dipole resonances between unit cells make the impedance of the absorber match to that of the free space, which induces two total absorption peaks in terahertz range. These absorption peaks are insensitive to the polarization and nearly omnidirectional for the incident angle. But the absorption intensity and frequency depend on material and geometric parameters of the multilayer structure. The absorbed electromagnetic waves are finally converted into heat and, as a result, the absorber shows a good nanosecond photothermal effect.

© 2015 Optical Society of America

Abstract-Graphene-based terahertz metasurface with tunable spectrum spli

Graphene-based terahertz metasurface with tunable spectrum splitting 

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-41-16-3799

Zhaoxian Su, Xuan Chen, Jianbo Yin, and Xiaopeng Zhao

We design a tunable terahertz metasurface, which consists of two different trapezoid graphene ribbons patterned in opposite directions on a gold film, separated by a thin dielectric spacer. The two kinds of graphene ribbons can cover a nearly 2𝜋 phase shift with high reflection efficiency in different spectral regions so that the metasurface can reflect different frequency waves to totally different directions. By changing the Fermi level of the graphene ribbons, the response frequency of the proposed metasurface can be adjusted, and as a result, tunable spectrum splitting can be realized. The present metasurface provides a powerful way to control terahertz waves and has potential applications in wide-angle beam splitters.

© 2016 Optical Society of America

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Abstract-Terahertz dual-band metamaterial absorber based on graphene/MgF2multilayer structures

Terahertz dual-band metamaterial absorber based on graphene/MgF2multilayer structures Zhaoxian Su, Jianbo Yin, and Xiaopeng Zhao  »View Author Affiliations

Optics Express, Vol. 23, Issue 2, pp. 1679-1690 (2015)
http://dx.doi.org/10.1364/OE.23.001679

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-23-2-1679

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We design an ultra-thin terahertz metamaterial absorber based on graphene/MgF₂ multilayer stacking unit cells arrayed on an Au film plane and theoretically demonstrate a dual-band total absorption effect. Due to strong anisotropic permittivity, the graphene/MgF₂ multilayer unit cells possess a hyperbolic dispersion. The strong electric and magnetic dipole resonances between unit cells make the impedance of the absorber match to that of the free space, which induces two total absorption peaks in terahertz range. These absorption peaks are insensitive to the polarization and nearly omnidirectional for the incident angle. But the absorption intensity and frequency depend on material and geometric parameters of the multilayer structure. The absorbed electromagnetic waves are finally converted into heat and, as a result, the absorber shows a good nanosecond photothermal effect.

© 2015 Optical Society of America