Optimized chemical potential graphene-based coding metasurface approach for dynamic manipulation of terahertz wavefront

Abstract

In this paper, a new method for the design of pixelated graphene-based coding metasurface is proposed. This method suggests a straightforward approach by utilizing graphene tunable pixels (GTPs), which can control the reflection phase in a real-time manner at terahertz (THz) frequencies. The proposed unit cell is composed of four distinct graphene patches in the same layer, which has a separate DC bias source. Each meta-atom can change the reflection phase by choosing appropriate chemical potential that obtained by utilizing optimization-based methods. By changing the reflection phase profile across the metasurface, the proposed device can manipulate the reflected wave dynamically. To investigate our proposed structure, we present a multifunctional reconfigurable metasurface to manipulate electromagnetic (EM) wave in the half-space and generate converged vortex beam, non-diffractive Bessel beam, and EM bump illusion. The simulation and theoretical results show that the suggested method offers a feasible strategy for multifunctional metasurface applications. Chemical potential optimization method in graphene-based coding metasurface is not limited to a specific structure for phase-only metasurface. Indeed it has an unique capability for phase, amplitude, and polarization control in various beamforming applications at THz spectrum for modern information systems, data encryption, and THz communication applications.

Graphene-Based Reconfigurable Intelligent Meta-Surface Structure for THz Communications

“…Graphene has been successfully used in reconfigurable metasurface structure for manipulation of terahertz waves due to its surface conductivity characteristics. Because of the boundary conditions in graphene, its radiation characteristics make it extremely sensitive to external excitation [7][8]. Conventionally, using external bias like voltage splitter which is controlled by FPGA, we can tune the AC conductivity of graphene [9].…”

Recent advances and perspectives on space-time coding digital metasurfaces

“…It appears therefore crucial to implement faster switching schemes, also with a view toward applications to higher frequencies (e.g., terahertz). Within this framework, emerging platforms based on graphene [55][56][57] and vanadium dioxide [58,59] seem very promising [60].…”

Terahertz smart dynamic and active functional electromagnetic metasurfaces and their applications

“…Moreover, compared with the surface plasmons in metal, the plasmons in graphene have a longer excitation lifetime and can be effectively tuned, which make this configuration suitable for application in the THz field [105][106][107]. It has been theoretically and experimentally proved that graphene can be used for THz devices in different domains, such as by using active metasurfaces [108,109], and newer, better devices can be developed [110][111][112][113][114][115][116][117][118]. However, it is necessary to improve the relevant mechanism and manufacturing technique to obtain advanced industrially applicable devices.…”