Abstract-Investigation of graphene assisted tunable terahertz metamaterials absorber

Xiaoyong He, Xu Zhong, Fangting Lin, and Wangzhou Shi
http://proxy.osapublishing.org/ome/abstract.cfm?uri=ome-6-2-331

By using the graphene-SiO2-Si-dielectrics-metallic ground plane (GSiO2SiDM) structures, we investigate the tunable properties of graphene metamaterials (MMs) absorbers in the terahertz region, including the effects of operation frequency, Fermi level, and graphene structure patterns. The results manifest that the graphene tunable GSiO2SiDM structure can achieve net absorption by changing structure parameters and the Fermi level of graphene layer. The resonant absorption and reflection curves of the GSiO2SiDM structures can be shifted in a wide range via controlling the applied electric fields. The modulation depth of resonant amplitude and frequency can reach more than 60% and 30%, respectively. The resonant peak (dip) of the absorption (reflection) curves shift to high frequency with the increase of Fermi level of the graphene layer. Due to broad absorption curve, the graphene MMs absorbers structures are suitable for the fabrication of broad absorber. The results are very useful to design novel devices, such as thermal detectors, imager, and biosensors.

© 2016 Optical Society of America

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Abstract-Investigation of the tunable properties of graphene complementary terahertz metamaterials

Xiaoyong HE,   Chunlin Liu,   Xu Zhong and   Wangzhou Shi  

RSC Adv., 2015, Accepted Manuscript

DOI: 10.1039/C4RA16762G
Accepted 09 Jan 2015
First published online 13 Jan 2015
http://pubs.rsc.org/en/content/articlelanding/2015/ra/c4ra16762g#!divAbstract

Based on the graphene-SiO2-Si structure, the tunable resonant properties of the complementary graphene metamaterials (MMs) have been investigated in the terahertz regime. The influence of operation frequency, the Fermi levels of graphene layer, and different kinds of graphene patterns have been taken into account. The results manifest that the tunable mechanisms of the complementary graphene MMs structures mainly depend on the LC resonance. The resonant transmission and reflection properties of the complementary graphene MMs structures can be tuned in a wide range via controlling the applied electric fields. As the Fermi level of graphene layer increases, the resonances of the MMs structure become stronger, and the resonant peaks of the transmission curves shift to the higher frequency, resulting from the permittivity of graphene layer increases in the THz regime. The transmission (reflection) spectrum is broad (sharp), which can be used to fabricate transmission modulator (reflection filters). The results are very helpful to design novel plasmonic devices and useful for the application of biomedical sensing and optical communications.


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