Electrically Tunable Perfect Terahertz Absorber Using Embedded Combline Graphene Layer

Maghoul, Amir; Rostami, Ali; Barzinjy, Azeez A.; Mirtaheri, Peyman

doi:10.3390/app112210961

Cited by 6 publications

(3 citation statements)

References 46 publications

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“…Further, a Drude model is considered to be determined the optical properties of gold material. In this model, the permittivity of bulk gold, the plasma frequency, and the damping constant are defined by ∞ = 1, ω p = 1.37 × 10 16 s −1 , and ω r = 1.23 × 10 14 s −1 , respectively [51,52]. Like before, a Gaussian pulse as incident light from the topside for excitation of the designed kit is utilized, illustrated by a wave port in the CST's simulation environment.…”

Section: Coronavirus Detection Using Graphene-based Nanosensormentioning

confidence: 99%

An Optical Modeling Framework for Coronavirus Detection Using Graphene-Based Nanosensor

et al. 2022

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The outbreak of the COVID-19 virus has faced the world with a new and dangerous challenge due to its contagious nature. Hence, developing sensory technologies to detect the coronavirus rapidly can provide a favorable condition for pandemic control of dangerous diseases. In between, because of the nanoscale size of this virus, there is a need for a good understanding of its optical behavior, which can give an extraordinary insight into the more efficient design of sensory devices. For the first time, this paper presents an optical modeling framework for a COVID-19 particle in the blood and extracts its optical characteristics based on numerical computations. To this end, a theoretical foundation of a COVID-19 particle is proposed based on the most recent experimental results available in the literature to simulate the optical behavior of the coronavirus under varying physical conditions. In order to obtain the optical properties of the COVID-19 model, the light reflectance by the structure is then simulated for different geometrical sizes, including the diameter of the COVID-19 particle and the size of the spikes surrounding it. It is found that the reflectance spectra are very sensitive to geometric changes of the coronavirus. Furthermore, the density of COVID-19 particles is investigated when the light is incident on different sides of the sample. Following this, we propose a nanosensor based on graphene, silicon, and gold nanodisks and demonstrate the functionality of the designed devices for detecting COVID-19 particles inside the blood samples. Indeed, the presented nanosensor design can be promoted as a practical procedure for creating nanoelectronic kits and wearable devices with considerable potential for fast virus detection.

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Section: Coronavirus Detection Using Graphene-based Nanosensormentioning

confidence: 99%

An Optical Modeling Framework for Coronavirus Detection Using Graphene-Based Nanosensor

et al. 2022

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“…Atomic thin active layers offer the advantage to prevent dephasing and dispersion of the propagating wave, if compared with III–V semiconductors. Single-layer graphene (SLG) is a highly nonlinear material (χ (3) ∼ 10 –9 m 2 /V 2 in the far-infrared) and it is thus ideal for integration into nonlinear optical devices. − SLG has zero band gap and large electrical tunability, which shifts the Fermi energy E F , and induces Pauli blocking of the optical transitions. − It also exhibits saturable absorption across a broad range of frequencies, − large nonlinear optical response , with a power transmission modulation of ∼ 50% per monolayer, − , ultrafast photoexcitation dynamics and recovery time, , high chemical and mechanical stability, large thermal, and optical threshold damage, and it is also an extremely efficient THz frequency multiplier, with a huge 3rd-order nonlinearity, , allowing for the direct generation of multiple harmonics in the 0.85–2.12 THz range. , …”

Section: Introductionmentioning

confidence: 99%

Electrically Tunable Nonlinearity at 3.2 Terahertz in Single-Layer Graphene

Di Gaspare,

Balci,

Zhang

et al. 2023

ACS Photonics

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Graphene is a nonlinear material in the terahertz (THz) frequency range, with χ (3) ∼ 10 −9 m 2 /V 2 ∼ 15 orders of magnitude higher than that of other materials used in the THz range, such as GaAs or lithium niobate. This nonlinear behavior, combined with ultrafast dynamic for excited carriers, proved to be essential for third harmonic generation in the sub-THz and low (<2.5 THz) THz range, using moderate (60 kV/cm) fields and at room temperature. Here, we show that, for monochromatic high peak power (1.8 W) input THz signals, emitted by a quantum cascade laser, the nonlinearity can be controlled using an ionic liquid gate that tunes the graphene Fermi energy up to >1.2 eV. Pump and probe experiments reveal an intense absorption nonlinearity at 3.2 THz, with a dominant 3rd-order contribution at E F > 0.7 eV, hence opening intriguing perspectives per engineering novel architectures for light generation at frequencies > 9 THz.

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“…This makes graphene promising in absorbers, tunable antennas, sensors, etc. (Yi et al 2017, Song 2020et al, Maghoul et al 2021, Fu et al 2023.…”

Section: Introductionmentioning

confidence: 99%

Integral equations in the H-polarized wave scattering from metasurface formed by finite multilayer graphene strip grating inside grounded dielectric slab

Kaliberda,

Pogarsky,

Sierhieieva

2023

Opt Quant Electron

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The H-polarized waves scattering and absorption by the metasurface, which consists of multilayer grating of finite number of graphene strips inside a grounded dielectric slab is considered. The problem is formulated in the domain of Fourier transform (spectral domain). The solution is obtained in two steps. At first, the scattering operators of a single graphene grating inside the infinite dielectric medium are obtained from the singular integral equations. At the second stage, the integral equations in the operator form relatively unknown Fourier amplitudes are presented for the whole structure. The kernel-functions of these equations contain singularities at the points, which correspond to the propagation constants of the natural waves of the dielectric waveguide with perfectly electric conducting wall.To eliminate the singularities and to convert the kernel-functions to the regular ones, the regularization procedure is proposed. The approach is meshless, fullwave and convergence is guaranteed by the theorems. The numerical results for the plane wave and natural wave of corresponding dielectric waveguide with perfectly electric conducting wall incidence are presented. Special attention is paid to the excitation of the plasmon and grating-mode resonances. By taking layers with different period and chemical potential, one can control the elevation angle of the main lobe and excitation frequency of the natural waves of dielectric waveguide.

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Electrically Tunable Perfect Terahertz Absorber Using Embedded Combline Graphene Layer

Cited by 6 publications

References 46 publications

An Optical Modeling Framework for Coronavirus Detection Using Graphene-Based Nanosensor

An Optical Modeling Framework for Coronavirus Detection Using Graphene-Based Nanosensor

Electrically Tunable Nonlinearity at 3.2 Terahertz in Single-Layer Graphene

Integral equations in the H-polarized wave scattering from metasurface formed by finite multilayer graphene strip grating inside grounded dielectric slab

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