Tunable and broadband coherent perfect absorbers with nonlinear and amplification performance based on asymmetric bifacial graphene metasurfaces

Abstract

We present an asymmetric bifacial graphene metasurface to realize tunable and broadband coherent perfect absorption (CPA) at terahertz (THz) frequencies. The proposed design is composed of two dissimilar graphene square patch metasurfaces stacked over an ultrathin dielectric substrate. Nonlinear CPA performance without resorting to optical nonlinearities and amplification are demonstrated based on wave interference phenomena taking place along and inside this subwavelength structure. Broadband asymmetric reflection from opposite directions is obtained in the case of single wave illumination. This response acts as a precursor to the presented tunable and broadband nonlinear CPA performance and the inverse response to absorption, i.e., amplification, when an additional input wave coherently interacts with the opposite propagating incident wave. The proposed ultrathin broadband CPA device is expected to be a vital component to several new on-chip THz communication devices, such as optical modulators, sensors, photodetectors, and all-optical small-signal amplifiers.

Broadband coherent perfect absorption by cavity coupled to three-level atoms in linear and nonlinear regimes

“…Our model can be applied to one-sided cavity [62], atom-optomechanical system [80][81][82], etc, easily. The experimental realization of CPA in CQED is meaningful for fabricating all-optical switching [70], interferometers [1], and logic elements [69] in several physical relevant frameworks, particularly in nonlinear optics [22,61], photonic lattice networks [83] and optical multiplexing [19].…”

“…With κ = Γ, we get g √ N = B/2 from equation (22). In this case, g 2 N > Γκ, the collective strong coupling condition is satisfied.…”

“…From then on, considerable theories and experiments about CPA are conducted. Now CPA phenomena have been demonstrated in different materials, including graphene [21,22], high-contrast grating [23,24], waveguide [25], photonic crystals [26], plasmonic array [27], etc [28]. Meanwhile, for extensive applications in biosensing [29], molecular detection [30], photovoltaics [31], photodetection [32,33], optical communications [34] and quantum informations, etc, CPA has been studied in a very broad wave range from acoustics [35], to infrared [18,[36][37][38][39] and optical frequencies [40][41][42][43][44][45].…”

Frequency-tunable wide-angle polarization selection with a graphene-based anisotropic epsilon-near-zero metamaterial

“…As a kind of two-dimensional materials, graphene has been widely investigated in the fields of physics and chemistry [29][30][31][32]. Owing to its good electrical and optical characteristics, various applications of graphene have arisen, including optical absorbers [33][34][35][36][37][38], optical mirrors [39], near-field radiative heat transfers [40][41][42], and electromagnetically induced transparency [43]. At terahertz frequencies, graphene is a kind of low-loss plasmonic materials [44,45].…”

Recent Advances in Terahertz Photonic Technologies Based on Graphene and Their Applications

“…These types of metasurfaces have attracted increased attention because of their various THz applications, such as broadband absorbers, modulators and filters, biosensors, tunable polarizers, light detectors, and cloaking devices. [10,[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] Furthermore, graphene is perfectly suited to be combined with metallic (plasmonic) or dielectric metamaterial or metasurface structures, cavities, and gratings due to its atomic-scale thickness and conformal nature. [14,16,29-3 33] The hybrid graphene-metamaterial design approach promises to further enhance the efficiency of light-graphene interactions.…”