A broadband metamaterial absorber based on multi-layer graphene in the terahertz region

Broadband Adjustable Terahertz Absorption in Series Asymmetric Oval-Shaped Graphene Pattern

“…With the rapid development of terahertz technology in the potential application prospects fields of imaging, security inspection, wireless communication, and sensing [1,2], high efficient and convenient terahertz devices becomes more urgent to meet these demands. As one of the key devices of terahertz system, terahertz absorber attracts the attention of many researchers [3][4][5][6][7][8][9]. However, the narrow bandwidth of terahertz wave absorber seriously limits its practicality.…”

Metal and graphene hybrid metasurface designed ultra-wideband terahertz absorbers with polarization and incident angle insensitivity

“…The design approaches for broadband graphene absorbers include single layer 44,45 and multi-layer structures. 3,[46][47][48][49] It must be pointed out that, though a second layer graphene was utilized in ref. 44 to play as a gate electrode, we still treat the structure as single layer.…”

“…In ref. 49, periodic graphene patterns are printed on a SiO 2 dielectric substrate and two-layer graphene lms are inserted in the substrate, and then, a wideband of 26.4% with absorptivity larger than 0.9 is obtained. For the multiple-layer technique, each layer generates a resonance, and then, the merging of the resonances effectively achieves a wide band.…”

Tunable terahertz broadband absorber based on a composite structure of graphene multilayer and silicon strip array

“…The surface conductivity of graphene depends on its chemical potential which can be controlled by gate voltage, magnetic field, electrostatic doping as well as optical excitation [10][11][12] . As a result, graphene can be used for designing THz functional devices such as filters [13] , reflectors [14] , modulators [15] , absorbers [16][17][18][19][20][21][22][23][24][25][26][27][28][29] and polarizers [30] . Focusing on THz absorbers, there are also various reported types including dual-frequency [16,17] , multifrequency [18] , broadband [19][20][21] or tunable absorption [22,23] .…”

“…Yin Zhang et al use a two-layer graphene grid and a cross-metal subwavelength structure to obtain narrow-band THz absorber with dynamic tunable absorption and polarization independence [21] . More publications by Xiong et al [22] , Rahmanzadeh et al [23,24] , Zou et al [25] , Xu et al [26] , Fu et al [27] , Fardoost et al [28] , Torabi et al [29] reported a number of absorbers based on graphene metamaterials. Most of these reported designs use multiple layers of patterned graphene and different graphene layer may have different absorption resonance.…”