Enhanced THz absorption of graphene cavity-based electromagnetic metamaterial structures

ABSTRACT

We investigate THz absorption characteristics of graphene cavity-based electromagnetic metamaterial structures by using the conductivity characteristic matrix method. We demonstrate that the proposed structure can obtain ideal terahertz absorption due to the strong localization of photons in the defect layer of the electromagnetic metamaterial structure. The THz absorption can be continuously adjusted from 0% to 100% by controlling the chemical potential of graphene through a gate voltage. The maximum THz absorption value can be tailored by adjusting the incident angle or the period number of the two PCs with respect to the graphene layer. The position of the THz absorption peak can be adjusted by changing the thickness ratio of the layers constituting the electromagnetic metamaterial structure. Our proposal may have potentially important applications in photodetectors, saturable absorbers, and photovoltaics.

KEYWORDS:

• Graphene cavity
• THz absorption characteristics
• electromagnetic metamaterial structure

Acknowledgments

This work was supported by the NSFC Grant Nos. 11664025 and 11964018, the NSF from the Jiangxi Province Nos. 20181BAB201017 and 20181BAB202027, the Open Research Fund of State Key Laboratory of Millimeter Waves No. K201606.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Natural Science Foundation of China [grant numbers 11664025 and 11964018], the Jiangxi Province Natural Science Foundation [grant numbers 20181BAB201017 and 20181BAB202027], the State Key Laboratory of Millimeter Waves [grant number K201606].