Enhanced Terahertz Absorption of Graphene Composite Integrated with Double Circular Metal Ring Array
- 191 Downloads
Graphene-based terahertz (THz) devices, such as modulators, detectors, and absorbers, play important roles in terahertz applications due to graphene’s effectively tunable terahertz absorption. The features of these terahertz devices are greatly related to the THz absorption of graphene. However, the monolayer graphene shows limited absorption to terahertz waves. In this paper, we demonstrated a new graphene composite with a double circular metal ring array deposited on graphene to enhance the absorption. The graphene composite consists of a double circular metal ring array, a monolayer graphene, silicon dioxide, and silicon substrates. The double circular metal ring array locally enhances the electromagnetic field on graphene and further increases graphene’s absorption. It shows that the peak absorption of the proposed graphene composite is increased to 95% for graphene Fermi level 0 eV at room temperature, which is more than seven times larger than that of the graphene composite without the double circular metal ring array. The enhanced terahertz absorption of the proposed graphene composite shows the potential ability of improving modulation depth and insertion loss of a THz reflection modulator.
KeywordsTerahertz absorption Graphene composite Double circular metal ring array Terahertz modulator
The authors acknowledge the VUB through the SRP-project M3D2. The authors also acknowledge Huizhou Speed Wireless Technology Co. Ltd. for offering the access of the commercial software HFSS and Bin Yu from this company for the technical assistance of the software usage.
- 5.Sensale-Rodriguez B, Yan R, Rafique S, Zhu M, Li W, Liang X, Gundlach D, Protasenko V, Kelly MM, Jena D, Liu L, Xing HG (2012) Extraordinary control of terahertz beam reflectance in graphene electro-absorption modulators. Nano Lett 12(9):4518–4522. https://doi.org/10.1021/nl3016329 CrossRefPubMedGoogle Scholar
- 7.Sensale-Rodriguez B, Yan R, Kelly MM, Fang T, Tahy K, Hwang WS, Jena D, Liu L, Xing HG (2012) Broadband graphene terahertz modulators enabled by intraband transitions. Nat Commun 3:780Google Scholar
- 14.Gao W, Shu J, Reichel K, Nickel DV, He X, Shi G, Vajtai R, Ajayan PM, Kono J, Mittleman DM, Xu Q (2014) High-contrast terahertz wave modulation by gated graphene enhanced by extraordinary transmission through ring apertures. Nano Lett 14(3):1242–1248. https://doi.org/10.1021/nl4041274 CrossRefPubMedGoogle Scholar
- 15.Nikitin AY, Guinea F, Garcia-Vidal FJ, Martin-Moreno L (2012) Surface plasmon enhanced absorption and suppressed transmission in periodic arrays of graphene ribbons. Phys Rev B 85(8):081405Google Scholar