Plasmonic Absorption Enhancement in Elliptical Graphene Arrays

Abstract

In this paper, we come up with a wavelength tunable absorber which is made up of periodically elliptical graphene arrays in the far-infrared and terahertz regions. Through simulation, we find that we can increase the length of long axis of the ellipse, raise the incidence angles of TM- and TE-polarization (TM- and TE-polarization indicate the direction of the incident electric field along the direction of the x and the y axis, respectively.) within certain limits, and increase the chemical potential of graphene, so as to enhance the absorption of light in the elliptical graphene arrays. We also compare the absorption spectra of the original structure and the complementary structure, and find that the absorption of the original structure is higher than that of the complementary structure. In the end, we study the changes in the absorption rate of the double layer structure of the elliptical array with the increase in the thickness of SiO2. The elliptical array structure can be applied to tunable spectral detectors, filters and sensors at far-infrared and terahertz wavelengths.

Electrically Tunable Broadband Terahertz Absorption with Hybrid-Patterned Graphene Metasurfaces

“…However, notably, a single-layer graphene is almost transparent owing to its relatively low carrier concentration [ 21 , 22 ]. To enhance the absorption of incident waves, a variety of resonance-relying narrowband absorbers with periodic structures such as patterned graphene disks [ 20 , 23 ], ribbons [ 24 ], and cross-shaped fishnets [ 25 ], have been proposed. Moreover, to increase the absorption bandwidth, the graphene-based tunable absorbers with the isolated multiresonator [ 26 ], non-structured graphene-dielectric brick structures [ 27 ], multilayer graphene structures [ 28 , 29 ], and structured graphene patterns have been investigated [ 30 , 31 , 32 ].…”

Graphene-Coated Nanowire Waveguides and Their Applications

“…Graphene [9], a two-dimensional (2D) carbon material, was proved to be an alternate material that could excite SPs in the mid and far-infrared bands owing to its unprecedented properties such as the tunability, extremely strong modal field confinement, and huge field enhancement [10][11][12]. Therefore, lots of graphene-based novel optical devices, including waveguides [13][14][15][16][17][18][19], modulators [20,21], switches [22][23][24], polarizers [25,26], sensors [27,28], antenna [29], etc., have been developed, and the research of graphene plasmonics has promoted the development of nanophotonics. Particularly, the GCNWs [30][31][32][33][34][35] have aroused lots of research interest, and the wide applications of GCNWs in photonic devices have become one of the research hot spots in recent years.…”

Tunable Multipolar Fano Resonances and Electric Field Enhancements in Au Ring-Disk Plasmonic Nanostructures

“…LSPRs have a lot of applications in many fields such as surface enhanced Raman spectroscopy (SERS), optical switches, telecommunications, biosensing, photocatalytics, and optical traps [ 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. The effective regulation of LSPRs is determined by the light polarization, structural parameters (size, shape), and surrounding environment of nanostructures [ 11 , 12 , 13 , 14 ]. Lately, the plasmonic Fano resonance that arises from the interaction between the dark plasmonic mode and the bright plasmonic mode is an interesting result of electro-magnetic coupling in nanostructures [ 15 , 16 ].…”