Graphene-Coated Nanowire Waveguides and Their Applications

Abstract

In recent years, graphene-coated nanowires (GCNWs) have attracted considerable research interest due to the unprecedented optical properties of graphene in terahertz (THz) and mid-infrared bands. Graphene plasmons in GCNWs have become an attractive platform for nanoscale applications in subwavelength waveguides, polarizers, modulators, nonlinear devices, etc. Here, we provide a comprehensive overview of the surface conductivity of graphene, GCNW-based plasmon waveguides, and applications of GCNWs in optical devices, nonlinear optics, and other intriguing fields. In terms of nonlinear optical properties, the focus is on saturable absorption. We also discuss some limitations of the GCNWs. It is believed that the research of GCNWs in the field of nanophotonics will continue to deepen, thus laying a solid foundation for its practical application.

The Light Absorption Enhancement in Graphene Monolayer Resulting from the Diffraction Coupling of Surface Plasmon Polariton Resonance

“…Due to the considerably good optical and electrical properties, graphene is known to hold a great promising potential in photoelectric devices, such as photodetectors, modulators, perfect absorbers, photovoltaics, photocatalysts, etc. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. However, the absorption efficiency of 2.3% is too low for the efficient operation of graphene-based photoelectric devices.…”

Theoretical Analysis of Terahertz Dielectric–Loaded Graphene Waveguide

“…Compared with the metallic waveguides, graphene plasmon waveguides could confine the infrared waves into the deep subwavelength scale, and the guided modes could be easily tuned [ 34 ]. Up to now, lots of graphene-based configurations have been proposed to guide the infrared waves, such as graphene ribbons [ 35 ], graphene slot waveguides [ 36 , 37 ], graphene wedge and groove waveguides [ 38 ], dielectric-loaded graphene waveguides [ 39 ], graphene-coated nanowires [ 40 , 41 , 42 , 43 , 44 , 45 , 46 ], graphene-based hybrid waveguides [ 47 , 48 ], etc.…”

Symmetric Graphene Dielectric Nanowaveguides as Ultra-Compact Photonic Structures

“…To address this critical challenge, researchers have suggested some available materials with tunable properties for exciting surface plasmons [ 21 ], including graphene [ 22 , 23 , 24 ], transition metal dichalcogenides [ 25 , 26 , 27 ], bulk Dirac semimetals [ 28 , 29 ], borophene [ 30 , 31 ], etc. Among these, graphene plasmons (GPs) have attracted widespread attention due to their advantages, including strong light–matter interactions, deep subwavelength field confinement, and tunable optical properties [ 23 , 24 ]. Benefiting from these excellent characteristics, graphene has served as an effective nanoscale waveguiding platform in the infrared region.…”