Coupling Controlled Dual‐Band Tunable Electromagnetic Extraordinary Transmission in Graphene Hybrid Metasurfaces

Abstract

by tailoring the geometry of the micro-/ nanostructures of subwavelength dimensions. [9][10][11][12] The metasurfaces with simple planar structures made of conventional metallic and dielectric materials have been used to manipulate EM wave in the amplitude, phase and polarization and complex wavefronts. [13][14][15][16][17][18][19][20][21][22][23][24] However, the operation frequency and performance of the metasurfaces made of conventional metallic/dielectric is limited in a narrow frequency range due to the static characteristic of the constituent materials. The static and narrowband function of metasurface may obstacle the practical applications.To overcome the static response, the fixed and narrow operation band of conventional metasurface, there have been various metadevices incorporated with materials or components responding to external stimuli such as electric elements, semiconductors, 2D materials, and perovskite materials [25][26][27][28][29][30][31] for tunable or multiple functionalities. [32][33][34] Graphene, i.e., the 2D carbon sheet with a honeycomb lattice, has led research upsurge in 2D materials. In photonics and optoelectronics, the properties of graphene can be tuned by electrostatic field, magnetic field, chemical doping, and optical pumping for wide-range tunability in a broad frequency range. [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] There have been scientific advances in graphene-based metasurfaces or metamaterials, especially in the terahertz and optical domain. [50][51][52] Also some progresses have also been made for lower frequency applications with large-scale graphene in, e.g., dynamical absorption, polarizer, and programmable metasurfaces. [53][54][55][56][57][58][59][60] It would be interesting to hybrid the large-scale graphene and novel transmissive metasurface for reconfigurable RF metadevices, e.g., metamodulator.The extraordinary optical transmission through subwavelength nanohole arrays was first reported by Ebbesen et al. [61] The enhanced transmission beyond classical aperture theory is due to the excitation of local surface plasmon modes. [62][63][64] Later, Aydin et al. [65] demonstrated that EET can be realized by properly design the local modes in meta-atom for extraordinarily enhanced EM wave transmission. [66,67] Here in this paper, we propose and demonstrate a kind graphene hybrid metasurface with tunable dual-band EET performance. The graphene hybrid metasurfaces are composed of perforated metallic layer A metasurface is a kind of ultrathin artificial composite composed of subwavelength elements with unique abilities in manipulating electromagnetic waves. However, the static nature of its conventional metallic/dielectric constituent material has limited its fixed functionality in narrow frequency ranges. The two-dimensional carbon sheet, i.e., graphene, is a promising platform for effectively tuning the functionality as well as operation frequency band of metasurface. Here, the authors propose and demonstrate a kind of graphene hybrid metasurface ...