Multifunctional graphene metasurface to generate and steer vortex waves

Abstract

Graphene, an innovated 2D material with atomic thickness, is a very promising candidate and has drawn great attentions in various applications. Graphene metasurface enables dynamic control of various wavefronts, achieving distinguished functionalities. The flexibility of graphene metasurface makes it possible to implement multifunctional devices with ease. In this work, a novel design of multifunctional graphene metasurface, which can combine the functionalities of generating and steering vortex waves, has been proposed. The multifunctional graphene metasurface consists of a large array of graphene reflective unit cells. Each unit cell is controlled independently by its size and external static gate voltage. By scrutinizing the reflective property of the graphene cell, the graphene metasurface is designed to realize multi-functionalities. Simulation results show that vortex wave can be generated and steered. This work can establish a methodology to design multifunctional graphene metasurfaces, and the tunability of graphene opens the gate to the design and fabrication of reconfigurable graphene devices.

Babinet-Complementary Structures for Implementation of Pseudospin-Polarized Waveguides

“…Furthermore, it is possible to incorporate impedance surfaces with dual capacitive-inductive nature thus allowing for forming unconventional passive circuits with dynamic configurations [30,36]. Especially, this includes graphene-based metasurfaces showing great potential applications in the terahertz and optical regimes [37][38][39]. As an illustration, Figure 8(a), and 8(b) shows an add-drop filter design that enables transforming EM energy along arbitrary paths simply by switching a capacitive/inductive impedance to inductive/capacitive impedance.…”

Graphene-Integrated Plasmonics Metasurface for Active Controlling Artificial Second Harmonic Generation

“…Co mpared with other method, graphene provides the gate voltage tenability of metamaterials with short response time and subwavelength interaction with electromagnetic field. Therefore, it has recently attracted considerable attention for its enormous applications of graphene in tunable metamaterials [33][34][35] and metasurfaces [37][38][39][40][41][42], such as electrically switchable cloaking devices [43], beam-steering in far field [44], tunable electromagnetically induced transparency [45], tunablemetamaterials for sensing [46], and tunable third-harmonic generation [47][48][49]. More importantly, the sensitivity of Fermi energy to the carrier density in the Dirac fermions results in ultrawide tunable space in responding external light fields, making it a feasible and outstanding platform for actively controllable plasmonics, especially at terahertz and far-infrared frequencies [50].…”

Analysis and design of terahertz reflectarrays based on graphene cell clusters

“…In another paper 31 , Carrasco proposed a tunable graphene unit-cell structure with a variable voltage bias, in order to control the complex conductivity of graphene to adjust the phase of reflected field. Later on, graphene reflectarrays were designed to create vortex beams in the terahertz range [32][33][34] . Unit-cells consisting of simple square graphene patches with electrical tuning capability, were implemented to steer the vortex beam.…”