Tunable polarization converter based on one-dimensional graphene metasurfaces

Tavakol, Mohammad Reza; Rahmani, Babak; Khavasi, Amin

doi:10.1364/josab.35.002574

Cited by 11 publications

(5 citation statements)

References 22 publications

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“…The necessary condition for linear to circular polarization conversion is that the magnitude of the co and cross polarization components must be equal with a phase difference of Δj = δ yx -δ xx = 2nπ ± 0.5π [29]. This can be easily checked with the help of stock parameters S 0 and S 3 .…”

Section: Resultsmentioning

confidence: 99%

“…The researchers made similar attempts to design wide-band polarizers for wide incident angles [20,[25][26][27][28]. Graphene has been extensively used as a tuning component in the literature by many researchers to manipulate the polarization of the incoming wave front in the THz regime [29][30][31]. In this work, we proposed a simple design that works as a linear polarization converter (LPC) and circular polarization converter (CPC).…”

Section: Introductionmentioning

confidence: 99%

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Active anisotropic polarization conversion meta-surface for 6G communication bandgap in the reflection mode

Jalal,

Qasim,

Qureshi

et al. 2023

Phys. Scr.

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This paper investigates a single-layered active anisotropic meta-surface design capable of achieving high polarization conversion efficiency in the 6 G communication band gap. Additionally, the designed structure can convert the linear polarization of the incoming wave fronts to its cross-polarization and linear polarization to circular polarization in the reflection mode. The polarization conversion characteristic is achieved due to the strong anisotropic behavior of the meta-surface. Such a simple design can achieve a 90% to 100% cross-polarization conversion efficiency over a frequency region of [0.28–0.36] THz. The linear to circular polarization conversion is performed near 0.26 THz and 0.40 THz. Between these two frequencies, band linear to cross-polarization conversion is more prominent. The proposed design can be tuned from a half-wave plate (HWP) or linear polarization converter to a quarter-wave plate (QWP) or circular polarization converter using the chemical potential of graphene. The optical response of the meta-surface behaves differently from different incident angles. The proposed polarization converter can contribute to the development of active polarization device.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Active anisotropic polarization conversion meta-surface for 6G communication bandgap in the reflection mode

Jalal,

Qasim,

Qureshi

et al. 2023

Phys. Scr.

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“…The graphene strips with the width of a = 5 μm are deposited on Quartz pillars with l = 22 μm and t = 1 μm. It is worth mentioning that vertical growth of the graphene layer was successfully modeled [62,63] and realized [64], adopting with the realm of current fabrication technologies. In our simulations, the relative permittivity and loss tangent of the Quartz substrate are ϵ r = 3.75 and tanδ = 0.0184, respectively.…”

Section: Re-programmable Polarizationmultiplexed Meta-hologrammentioning

confidence: 99%

“…The key point is that all our designed coding elements depict a high reflectivity over the operating bandwidth as they function far from their resonance frequency. Since the effective guided index of such structure is nearly independent of the frequency [63], the reflection phase responses have a nearly linear trend, which is very crucial for designing multi-bit bias-encoded metaatoms with identical geometries. Since the intrinsic loss of graphene layers, the full reflection phase span of 360°has not been achieved; however, the phase span of 315°is sufficient to provide good performance in holographic applications [67].…”

Section: Re-programmable Polarizationmultiplexed Meta-hologrammentioning

confidence: 99%

Real-time terahertz meta-cryptography using polarization-multiplexed graphene-based computer-generated holograms

et al. 2020

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AbstractAs one of the cutting-edge technologies in advanced information science, wave-based cryptography is a prerequisite to enable a plethora of secure encrypting platforms which can be realized by smart multiplexing techniques together with suitable metasurface holograms (meta-holograms). Here, relying on the polarization multiplicity and re-writability of a computer-generated meta-hologram, a fully secure communication protocol is elaborately developed at the terahertz spectrum to host unique merits for exploring real-time metasurface-based cryptography (meta-cryptography) where highly restricted access of information is imposed. The proposed meta-cryptography exploits two dynamic near-field channels of a meta-hologram whose information can be instantaneously re-written without any polarization rotation and with high contrast and acceptable frequency bandwidth. The computer-generated meta-hologram is constructed based on the weighted Gerchberg–Saxton algorithm via a two-dimensional array of vertical graphene strips whose anisotropic reflection is merely determined by external biasing conditions. Several illustrative examples have been presented to demonstrate the perfect secrecy and polarization cross-talk of the proposed meta-cryptography. Numerical simulations corroborate well our theoretical predictions. As the first demonstration of dynamic THz meta-cryptography, the meta-hologram information channels can be deciphered into manifold customized messages which would be instrumental in data storage systems offering far higher data rates than electronic encryption can deliver.

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“…In [14], a polarization converter based on a system of double-layer graphene embedded into periodically arranged dielectric pillars with a slab situated on PEC plane is presented. The calculations are carried out in COMSOL Multiphysics.…”

Section: Introductionmentioning

confidence: 99%

Scattering of the H-polarized plane wave by finite and semi-infinite multilayer systems of infinite graphene strip gratings in the THz range

Калиберда

Lytvynenko

Pogarsky

2019

Int. J. Microw. Wireless Technol.

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We consider the scattering and absorption of the H-polarized plane wave by finite and semi-infinite systems of layers in the THz range. Every layer consists of an infinite graphene strip grating embedded into a dielectric slab. The solution of the problem we obtain in several steps. First, with the use of the method of singular integral equations we obtain scattering matrices of a single layer. Then, we present equations for the finite and semi-infinite systems of layers relatively the Fourier amplitudes of the scattered field. The frequency dependences of the reflection, transmission, and absorption coefficients demonstrate the variety of resonances: plasmon, slab-mode, grating-mode resonances, and resonances of the multilayer structure.

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Tunable polarization converter based on one-dimensional graphene metasurfaces

Cited by 11 publications

References 22 publications

Active anisotropic polarization conversion meta-surface for 6G communication bandgap in the reflection mode

Active anisotropic polarization conversion meta-surface for 6G communication bandgap in the reflection mode

Real-time terahertz meta-cryptography using polarization-multiplexed graphene-based computer-generated holograms

Scattering of the H-polarized plane wave by finite and semi-infinite multilayer systems of infinite graphene strip gratings in the THz range

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