scholarly journals Right-Angle Shaped Elements as Dual-Band Metamaterial Absorber in Terahertz

2019 ◽  
Vol 10 (3) ◽  
pp. 233-241
Author(s):  
Salman Daniel ◽  
Prince Bawuah
Keyword(s):  
Electromagnetic Wave ◽  
Numerical Simulations ◽  
Metamaterial Absorber ◽  
Terahertz Range ◽  
Dual Band ◽  
Angle Of Incidence ◽  
Wide Range ◽  
State Of Polarization ◽  
Potential Applications ◽  
Metamaterial Absorbers

AbstractMetamaterial absorbers display potential applications in the field of photonics and have been investigated extensively during the last decade. We propose a dual-band resonant metamaterial absorber with right-angle shaped elements (RAEs) in the terahertz range based on numerical simulations. The absorber remains insensitive to a wide range of incidence angles (0°–70°) by showing a minimum absorbance of ~80% at 70°. Furthermore, the proposed absorber is highly independent on any state of polarization of the incidence electromagnetic wave due to the high absorbance, i.e., greater than 80%, recorded for the considered polarization states. To further comprehend the slight variations in absorbance as a function of change in the angle of incidence, the impedance of the structure has been critically examined. The metamaterial absorber is simple in design, and we provide a possible path of fabrication.

Strong absorption of solar energy by using wide band metamaterial absorber designed with plus-shaped resonators

2018 ◽  
Vol 32 (25) ◽  
pp. 1850275 ◽  
Author(s):  
Emin Ünal ◽  
Mehmet Bağmancı ◽  
Muharrem Karaaslan ◽  
Oguzhan Akgol ◽  
Cumali Sabah
Keyword(s):  
Frequency Band ◽  
Metal Layer ◽  
Wide Band ◽  
Metamaterial Absorber ◽  
Dual Band ◽  
Polarization Angle ◽  
Perfect Absorption ◽  
Tem Mode ◽  
Potential Applications ◽  
Absorption Level

A new metamaterial absorber (MA) having distinct properties than those given in the literature is investigated. Although several designs have been studied for achieving absorption characteristics in single-band, dual-band and multiple bands within the whole spectrum of solar light, there has been limited number of researches examining the broadband MA in the visible light section of the spectrum. The designed structure is composed of the combination of three layers having different thicknesses including a metallic substrate, dielectric and a metal layer. Due to the sandwich-like structure, it can support the plasmonic resonance. The proposed structure, which provides a maximum absorption level of 99.42% at 579.26 THz, has a high absorption rate of 99% between the frequency band 545 and 628 THz. Numerical results indicate that the proposed structure has perfect absorption which is greater than 90.98% through the whole working frequency band. The dependency of the designed structure on the polarization angle is investigated for different incident angles with TE and TM polarizations as well as the TEM mode. In addition to its potential applications such as solar cells and cloaking, the designed structure can also be considered as a color sensor and an optical frequency sensor.

scholarly journals Three-Dimensional Resistive Metamaterial Absorber Loaded with Metallic Resonators for the Enhancement of Lower-Frequency Absorption

2017 ◽  
Author(s):  
Yang Shen ◽  
Jie Qiu Zhang ◽  
Yong Qiang Pang ◽  
Lin Zheng ◽  
Jia Fu Wang ◽  
...  
Keyword(s):  
Absorption Band ◽  
Three Dimensional ◽  
Areal Density ◽  
Metamaterial Absorber ◽  
Experimental Results ◽  
Broadband Absorption ◽  
Three Samples ◽  
Wide Range ◽  
Metamaterial Absorbers

Resistive patch array incorporating with metallic backplane provided an effective way to the achievement of broadband metamaterial absorbers(MAs). When loading metallic metamaterial to resistive MA, the outstanding construction helps realize more flexible and diversified forms of broadband absorption. In this paper, we attempted to load metallic resonators(MRs) to resistive MA in the three-dimensional construction, which benefits further enhancement of lower-frequency absorption. Simulation showed that the partial absorption band was separated to lower frequency, while the rest of broadband absorption was unaffected. Meanwhile, after combining multi-unit of the proposed MAs, the stair-stepping broadband absorption was also achieved. At last, three samples were fabricated. The agreements between simulations and experimental results demonstrated that resistive MA loaded with MRs provided an effective way for further enhancement of lower-frequency absorption with almost no change of the absorbing structure and areal density. Thus, it is worthy to expect a wide range of applications to emerge inspired from the proposed attempt.

scholarly journals Modified nonlinear Schrödinger models, 𝒞𝒫s𝒯d invariant N-bright solitons and infinite towers of anomalous charges

2021 ◽  
pp. 2150272
Author(s):  
H. Blas ◽  
M. Cerna Maguiña ◽  
L. F. dos Santos
Keyword(s):  
Numerical Simulations ◽  
Type Systems ◽  
Einstein Condensation ◽  
Anomaly Cancellation ◽  
Nonlinear Schrödinger ◽  
Bright Solitons ◽  
Wide Range ◽  
Potential Applications ◽  
Special Complex ◽  
Bose Einstein

Modifications of the nonlinear Schrödinger (MNLS) model [Formula: see text] where [Formula: see text] and [Formula: see text], are considered. We show that the MNLS models possess infinite towers of quasi-conservation laws for soliton-type configurations with a special complex conjugation, shifted parity and delayed time reversion ([Formula: see text]) symmetry. Infinite towers of anomalous charges appear even in the standard NLS model for [Formula: see text] invariant [Formula: see text]-bright solitons. The true conserved charges emerge through some kind of anomaly cancellation mechanism. Our analytical results are supported by numerical simulations of two-bright-soliton scatterings with potential [Formula: see text]. Our numerical simulations show the elastic scattering of bright solitons for a wide range of values of the set [Formula: see text] and a variety of amplitudes and relative velocities. The MNLS-type systems are quite ubiquitous, and so, our results may find potential applications in several areas of nonlinear physics, such as Bose–Einstein condensation, superconductivity, soliton turbulence and the triality among gauge theories, integrable models and gravity theories.

scholarly journals Dual-Band Perfect Metamaterial Absorber Based on an Asymmetric H-Shaped Structure for Terahertz Waves

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2193 ◽  
Author(s):  
Taiguo Lu ◽  
Dawei Zhang ◽  
Peizhen Qiu ◽  
Jiqing Lian ◽  
Ming Jing ◽  
...  
Keyword(s):  
Metamaterial Absorber ◽  
Dual Band ◽  
Interference Theory ◽  
Metamaterial Structure ◽  
Terahertz Waves ◽  
Potential Applications ◽  
Band Absorption ◽  
Perfect Metamaterial Absorber ◽  
Simulation Results ◽  
Absorption Frequencies

We designed an ultra-thin dual-band metamaterial absorber by adjusting the side strips’ length of an H-shaped unit cell in the opposite direction to break the structural symmetry. The dual absorption peaks approximately 99.95% and 99.91% near the central resonance frequency of 4.72 THz and 5.0 THz were obtained, respectively. Meanwhile, a plasmon-induced transmission (PIT) like reflection window appears between the two absorption frequencies. In addition to theoretical explanations qualitatively, a multi-reflection interference theory is also investigated to prove the simulation results quantitatively. This work provides a way to obtain perfect dual-band absorption through an asymmetric metamaterial structure, and it may achieve potential applications in a variety of fields including filters, sensors, and some other functional metamaterial devices.

scholarly journals Actively modulated propagation of electromagnetic wave in hybrid metasurfaces containing graphene

2020 ◽  
Vol 7 ◽  
pp. 9
Author(s):  
Jiameng Nan ◽  
Ruisheng Yang ◽  
Jing Xu ◽  
Quanhong Fu ◽  
Fuli Zhang ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Fermi Level ◽  
Numerical Simulations ◽  
Sandwich Structure ◽  
Modulation Depth ◽  
Metallic Structure ◽  
Transmission Amplitude ◽  
Wide Range ◽  
Resonance Transmission ◽  
Good Agreement

Here we present the actively modulated transportation of electromagnetic wave through hybrid metasurfaces containing graphene. The hybrid metasurfaces are composed of patterned metallic layers of extraordinary transmission and backed with graphene-sandwich layers. With the designed metallic layer with perforated structure, we demonstrated effective modulation on the on-resonance transmission amplitude by increasing the bias voltage from 0 to 4 V to electrically tune the Fermi level as well as the sheet resistance of the graphene-sandwich structure. We also found that the modulation depth can be further improved by properly designing the perforated metallic structure. By change the geometry from cut-wire structure to the “butterfly”-like pattern we preliminarily achieved 19.2% improvement on the on-resonance transmission modulation. The measured transmittances of the active metasurfaces show good agreement with the numerical simulations with fitted graphene sheet resistances. The hybrid metasurfaces presented in this work may be deployed in a wide range of applications based on active electromagnetic or optical modulations.

scholarly journals Broadband Bi-Directional Polarization-Insensitive Metamaterial Absorber

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7339
Author(s):  
Feng Tian ◽  
Xia Ma ◽  
Han Hao ◽  
Xuewen Li ◽  
Jingdao Fan ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Impedance Matching ◽  
Middle Layer ◽  
Metamaterial Absorber ◽  
Metal Plate ◽  
Equivalent Circuits ◽  
Practical Applications ◽  
Polarization Insensitive ◽  
Absorption Performance ◽  
Metamaterial Absorbers

Conventional metamaterial absorbers eliminate the transmitted electromagnetic wave by attaching the metal plate with the unidirectional absorption performance; these absorbers limit the practical applications to a large extent. In this paper, we present a broadband bi-directional metamaterial absorber by etching chip resistors on the resonators for expanding the bandwidth, and two orthogonal I-shaped structures are pasted on the both sides of the ultra-thin substrate (FR-4) instead of the metal plate for enhancing absorptance of the absorber. Simulated results show that absorptance of the designed absorber is larger than 0.9 in 1.43–2.51 GHz along the forward and backward directions under both TE and TM polarizations. Microwave experiments in the chamber are performed to verify the simulations, and the experimental results exhibit the excellent agreement with the simulations. Additionally, two I-shaped structures are orthogonally pasted on an ultrathin substrate, leading to the impedance-matching of both forward and backward directions, and the absorptance can be tailed dynamically via the middle layer of the substrate. The physics of the absorption are visualized by using a transmission line based on equivalent circuits. We claim that the designed bi-directional metamaterial absorber can be a good candidate for electromagnetic stealth and energy harvesting.

scholarly journals Experimental Verification of a TH\(\text{z}\) Multi-band Metamaterial Absorber

2020 ◽  
Vol 30 (4) ◽  
pp. 311
Author(s):  
Van Huynh Tran ◽  
Thanh Tung Nguyen ◽  
Xuan Khuyen Bui ◽  
Dinh Lam Vu ◽  
Son Tung Bui ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Experimental Verification ◽  
Metamaterial Absorber ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Dielectric Spacer ◽  
Wide Range ◽  
Band Absorption ◽  
Absorption Performance ◽  
Metamaterial Absorbers ◽  
Multi Band

Multi-band metamaterial absorbers have been of great interest owing to their potentials for a wide range of communicating, sensing, imaging, and energy harvesting applications. In this work, we experimentally investigate a four-band metamaterial absorber operating at THz frequencies. The metamaterials are fabricated using the maskless UV photolithography and e-beam evaporation techniques. The absorption spectra of the proposed absorber are measured using the micro-Fourier transformed infrared spectroscopy. It was demonstrated that multi-band absorption behavior originates from different individual metamaterial resonators. The thickness of the dielectric spacer plays a key role in optimizing the absorption performance, in line with the predicted results on single-band THz absorbers.

scholarly journals Design of Dual-Band Terahertz Perfect Metamaterial Absorber Based on Circuit Theory

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4104
Author(s):  
Zhongmin Liu ◽  
Liang Guo ◽  
Qingmao Zhang
Keyword(s):  
Chemical Potential ◽  
Metamaterial Absorber ◽  
Circuit Model ◽  
Field Analysis ◽  
Dual Band ◽  
Geometrical Parameters ◽  
Absorption Bands ◽  
Perfect Absorption ◽  
Wide Range ◽  
Novel Strategy

We present a novel strategy for designing a dual-band absorber based on graphene metasurface for terahertz frequencies. The absorber consists of a two-dimensional array of patches deposited on a metal-backed dielectric layer. Using an analytical circuit model, we obtain closed-form relatinos for the geometrical parameters of the absorber and the properties of the applied materials to achieve the dual-band absorber. Two absorption bands with perfect absorption at the preset frequencies of 0.5 and 1.5 THz are achieved. The results obtained by the analytical circuit model are compared to the simulations carried out by full-wave electromagnetic field analysis. The agreement between results is very good. We demonstrate that the graphene absorber remains as the dual band for a wide range of the chemical potential. Furthermore, the recommended dual band absorber is insensitive in terms of polarization and remain within various incident angles.

Variable Angle Spectroscopic Ellipsometry (VASE) for the Study of Ion-Beam and Growth-Modified Solids

1987 ◽  
Vol 93 ◽  
Author(s):  
John A. Woollam ◽  
Paul G. Snyder ◽  
M. C. Rost
Keyword(s):  
Ion Beam ◽  
Polarized Light ◽  
Stepper Motor ◽  
Angle Of Incidence ◽  
Wide Range ◽  
State Of Polarization ◽  
Linearly Polarized ◽  
Variable Angle Spectroscopic Ellipsometry ◽  
The University ◽  
Elliptically Polarized

In the most commonly used form of ellipsometry, a monochromatic collimated linearly polarized light beam is directed at an angle φ to the normal of a sample under study. The specularly reflected beam is, in general, elliptically polarized, and the state of polarization is analyzed using a second polarizer and photodetector.1 Figure 1 shows a schematic of the rotating analyzer automated spectroscopic ellipsometer used at the University of Nebraska. The angle of incidence can be set over a wide range of angles, with a precision and repeatability of ±0.01 angular degrees. A computer controls the monochromator, the azimuth of a stepper motor driven polarizer, a shutter, and the digitization of the detector signal. There are several other schemes used for acquiring ellipsometric data, and these are discussed in several sources.

Implementation of a perfect metamaterial absorber into multi-functional sensor applications

2017 ◽  
Vol 31 (15) ◽  
pp. 1750176 ◽  
Author(s):  
O. Akgol ◽  
M. Karaaslan ◽  
E. Unal ◽  
C. Sabah
Keyword(s):  
Dielectric Properties ◽  
Numerical Simulations ◽  
Microwave Frequency ◽  
Metamaterial Absorber ◽  
Frequency Range ◽  
Sensor Applications ◽  
Potential Applications ◽  
Perfect Metamaterial Absorber

Perfect metamaterial absorber (MA)-based sensor applications are presented and investigated in the microwave frequency range. It is also experimentally analyzed and tested to verify the behavior of the MA. Suggested perfect MA-based sensor has a simple configuration which introduces flexibility to sense the dielectric properties of a material and the pressure of the medium. The investigated applications include pressure and density sensing. Besides, numerical simulations verify that the suggested sensor achieves good sensing capabilities for both applications. The proposed perfect MA-based sensor variations enable many potential applications in medical or food technologies.

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