Strong interaction between graphene layer and Fano resonance in terahertz metamaterials

Abstract

Abstract. Graphene has emerged as a promising building block in the modern optics and optoelectronics due to its novel optical and electrical properties. In the midinfrared and terahertz (THz) regime, graphene behaves like metals and supports surface plasmon resonances (SPRs). Moreover, the continuously tunable conductivity of graphene enables active SPRs and gives rise to a range of active applications. However, the interaction between graphene and metal-based resonant metamaterials has not been fully understood. In this work, a simulation investigation on the interaction between the graphene layer and THz resonances supported by the two-gap split ring metamaterials is systematically conducted. The simulation results show that the graphene layer can substantially reduce the Fano resonance and even switch it off, while leave the dipole resonance nearly unaffected, which phenomenon is well explained with the high conductivity of graphene. With the manipulation of graphene conductivity via altering its Fermi energy or layer number, the amplitude of the Fano resonance can be modulated. The tunable Fano resonance here together with the underlying physical mechanism can be strategically important in designing active metal-graphene hybrid metamaterials. In addition, the "sensitivity" to the graphene layer of the Fano resonance is also highly appreciated in the field of ultrasensitive sensing, where the novel physical mechanism can be employed in sensing other graphene-like twodimensional (2D) materials or biomolecules with the high conductivity.

Terahertz ultrasensitive biosensing metamaterial and metasurface based on spoof surface plasmon polaritons

“…19,20 On the basis of SSPPs, a growing number of planar THz metamaterial structures have been reported, such as fishnet structure, microsize split ring resonance, corrugated metal stripe structure, and graphene-based structures. [21][22][23][24][25][26][27] More interestingly, the variation in refractive index of the material cladding on the metal surface will change the propagation constant of the SSPPs, the resonance wavelength, the mode field distribution, and the phase of guided optical wave. 28 Thus, it provides another significant sensing method in THz regime to effectively detect the micro changes in DNA or RNA, polypeptide, and aminophenol of biological cells or tissues.…”

Plasmonic absorption characteristics based on dumbbell-shaped graphene metamaterial arrays

“…In the lower THz range, the interband contributions can be completely ignored. Because of Pauli exclusion principle, the surface conductivity can be approximated as a Drude-like model [41,42].…”

Graphene-based tunable plasmon induced transparency in gold strips

“…Graphene has remarkable properties, which has made it an active research area for the last decade [25][26][27]. At mid-infrared (MIR) graphene has tight field confinement [28] and a controllable E f with gate voltage [29][30][31][32], which makes graphene a suitable candidate for tuning resonances electrically. The interaction of light with graphene can be explained by the concept of Pauli Blocking [33], as graphene forms a conical band diagram.…”