Multi-bit graphene-based bias-encoded metasurfaces for real-time terahertz wavefront shaping: From controllable orbital angular momentum generation toward arbitrary beam tailoring

Analytical and rigorous method for analysis of an array of magnetically-biased graphene ribbons

“…As in the case of a single ribbon, we first treat the equation for J y . However, the interaction between ribbons, manifested in the periodic Green's function (12), leads to an important modification of the approximation (5). For sub-wavelength arrays where k 0 D 1, a lengthy calculation presented in the appendix shows that…”

“…Consider the Green function (12). The Hankel function is written as were the integration is carried out over the path shown on page 916 of [33] in the complex θ plane.…”

“…This tunability provides additional flexibility in the design of diverse functionalities. Therefore, numerous graphene-based applications have been proposed from microwave to terahertz regions [5], [6], [7], [8], [9], [10], [11], [12] Under an external magnetic bias, the surface conductivity of graphene becomes a tensor, and it will also have non-reciprocal properties [13]. These extraordinary properties make graphene a promising material for many novel applications, such as isolators [14], nonreciprocal couplers [15], optical modulators [16], and Faraday rotators [17], in the terahertz regime.…”

Flexible Manipulation of Emitting Beams Using Single‐Aperture Circularly Polarized Digital Metasurface Antennas: Multi‐Beam Radiation toward Vortex‐Beam Generation

“…Recent years have witnessed a clear tendency toward achieving multiple contour beams using fully planar metasurface‐based devices with a lighter weight and lower cost compared to the solid reflectors [ 6 ] and bulky metamaterials. [ 7 ] Metasurfaces, engineered arrays of artificially patterned microelements on a flat surface, have recently emerged as a flourishing concept which attracts tremendous interest because of providing peculiar routes to manipulate the phase, [ 8–10 ] polarization, [ 11 ] amplitude, [ 12–14 ] transversal shape, [ 15,16 ] and trajectory [ 17–20 ] of the electromagnetic (EM) fields. Since Capasso's group introduced the generalized laws of refraction/reflection in 2011, [ 21 ] this 2D version of metamaterials has inspired many exceptional and modern devices, typically in the field of antennas and antenna accessories.…”

Parallel integro-differential equation solving via multi-channel reciprocal bianisotropic metasurface augmented by normal susceptibilities

“…In another context, metasurfaces are known as two-dimensional versions of the metamaterial family [23] at subwavelength scales which cover a broad scope of applications due to their strong interactions with light and ease of fabrication [24]. They provide prominent abilities for polarizing [25][26][27][28], absorbing [29][30][31][32], channeling [33][34][35][36][37][38][39][40], and processing [41][42][43][44] waves, especially within optical frequencies. Several analytical frameworks have been recently developed to synthesize metasurfaces at microscopic to macroscopic scales such as impedance/ admittance matrices [45,46], generalized sheet transition conditions (GSTCs) by susceptibility tensors [47,48], polarizability tensors [49][50][51], and local complex scattering parameters [39,[52][53][54].…”