scholarly journals Research on Perfect and Tunable Metamaterial Absorber Based on Crosshair-shaped Graphene

2021 ◽  
Vol 2109 (1) ◽  
pp. 012015
Author(s):  
Yiran Guo ◽  
Yunping Qi ◽  
Chuqin Liu ◽  
Weiming Liu ◽  
Xiangxian Wang
Keyword(s):  
Relaxation Time ◽  
Chemical Potential ◽  
Incident Angle ◽  
Fdtd Method ◽  
Reference Value ◽  
Metamaterial Absorber ◽  
Selective Absorption ◽  
Perfect Absorber ◽  
Wide Angle ◽  
Perfect Absorption

Abstract Graphene, as a new nano-material, according to the physical properties of electric field localization and selective absorption on light of surface plasmon resonance (SPR), a tunable, multi-band and wide-angle perfect absorber based on crosshair-shaped graphene is devised by using the Finite Difference in Time Domain (FDTD) method. In this paper, the effects of chemical potential, relaxation time, and incident angle of light on the absorptivity of graphene are systematically discussed. The simulation experiment shows that there are two absorption peaks with perfect absorption rate appeared in the study range, and the maximum modulation index can be obtained by changing the relaxation time. Finally, it proves that the absorber is insensitive to wide-angle of light. Thus, it is able to be concluded that the absorber has a great reference value to sensor, wireless communication, biomedical and other fields.

scholarly journals Hybrid Metamaterials Perfect Absorber and Sensitive Sensor in Optical Communication Band

2021 ◽  
Vol 9 ◽  
Author(s):  
Xuehan Liu ◽  
Keyang Li ◽  
Zhao Meng ◽  
Zhun Zhang ◽  
Zhongchao Wei
Keyword(s):  
Optical Communication ◽  
Electromagnetic Waves ◽  
Incident Angle ◽  
Silicon Layer ◽  
Resonance Wavelength ◽  
Metamaterial Absorber ◽  
Absorption Peak ◽  
Dual Band ◽  
Perfect Absorber ◽  
Perfect Absorption

A subwavelength metamaterial perfect absorber (MPA) in optical communication band was proposed and tested using the finite-difference time-domain method. The absorber is periodic and comprises a top layer of diamond silicon surrounded by L-shaped silicon and a gold layer on the substrate. It can achieve dual-band perfect absorption, and one of the peaks is in the optical communication band. By changing the gap (g) between two adjacent pieces of L-shaped silicon, and the thickness (h) of the silicon layer, the resonance wavelength of absorption peak can be tuned. When the incident electromagnetic wave entered the absorber, the metamaterial absorber could almost completely consume the incident electromagnetic waves, thereby achieving more than 99% perfect absorption. The absorption peak reaches 99.986% at 1310 nm and 99.421% at 1550 nm. Moreover, the MPA exposed to different ambient refraction indexes can be applied as plasma sensors, and can achieve multi-channel absorption with high figure of merit (FOM*) value and refractive index (RI) sensitivity. The FOM* values at 1310 nm and 1550 nm are 6615 and 168, respectively, and both resonance peaks have highly RI sensitivity. The results confirm that the MPA is a dual-band, polarization-independent, wide-angle absorber and insensitive to incident angle. Thence it can be applied in the fields of optical communication, used as a light-wave filter and plasma sensor, and so on.

scholarly journals Wide-angle infrared plasmonic perfect absorber based on graphene-silica grating

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Fang Chen
Keyword(s):  
Chemical Potential ◽  
Dual Band ◽  
Infrared Range ◽  
Perfect Absorber ◽  
Spectral Position ◽  
Wide Angle ◽  
Perfect Absorption ◽  
Layer Graphene ◽  
Wide Range ◽  
Graphene Strip

In this paper, wide-angle infrared perfect absorption has been demonstrated by using a double-layer graphene strip grating coupled with a silicon dioxide grating. Numerical simulation of the finite-difference time-domain method indicates that the perfect absorption can be achieved due to the effective impedance matching, and all the incident electromagnetic energy is confined in the Al2O3 layer between the silver substrate and the graphene strip grating. Dual-band perfect absorption is achieved with the change of strip width or chemical potential of the bi-layer graphene strip grating. It is found that the spectral position of the absorption peak can be tuned by the chemical potential or the width of the graphene strip, and additionally by the size of the proposed absorber. Moreover, the proposed perfect absorber shows excellent absorption stability for a wide range of the incident angle up to ±65°. The proposed absorber may find potential application in tunable double band perfect absorbers in the mid-infrared range.

Reversibly-propagational metamaterial absorber for sensing application

2018 ◽  
Vol 32 (04) ◽  
pp. 1850044 ◽  
Author(s):  
Bui Son Tung ◽  
Bui Xuan Khuyen ◽  
Young Joon Yoo ◽  
Joo Yull Rhee ◽  
Ki Won Kim ◽  
...  
Keyword(s):  
Oblique Incidence ◽  
Geometrical Structure ◽  
Incident Angle ◽  
Metamaterial Absorber ◽  
Perfect Absorber ◽  
Perfect Absorption ◽  
Great Magnitude ◽  
X Band ◽  
Sensing Application ◽  
Metamaterial Perfect Absorber

We investigated a reversibly-propagational metamaterial perfect absorber (MPA) for X band using two separated identically-patterned copper layers, which were deposited on continuous dielectric FR-4 layers. By adjusting oblique incidence, two separated resonances are excited, then come close to each other and is finally merged to be a perfect absorption peak at 10.1 GHz. The nature of resonance is the quadrupole mode instead of the fundamental resonances in common MPAs. The mechanism of perfect absorption is the coupling of two quadrupole resonances at their superposition, leading to an enhancement of energy absorption. Finally, we numerically presented the capability of sensing thin resonant substance using the proposed MPA. The characteristic resonance of substance, which does not appear on the absorption spectrum at the limited thickness of bare substance layer, is detected with a great magnitude of signal by exploiting the absorption resonance of MPA. Our work provides another way to obtain the reversibly-propagational absorption by controlling the incident angle instead of the geometrical structure, and might be useful for the potential devices based on MPA such as detectors and sensors.

A dynamically tunable and wide-angle terahertz absorber based on graphene-dielectric grating

2020 ◽  
Vol 34 (27) ◽  
pp. 2050292
Author(s):  
Chunyan Wu ◽  
Yiqiang Fang ◽  
Linbao Luo ◽  
Kai Guo ◽  
Zhongyi Guo
Keyword(s):  
Chemical Potential ◽  
Incident Angle ◽  
Near Field ◽  
Absorption Efficiency ◽  
Multilayer Graphene ◽  
Wide Angle ◽  
Terahertz Absorber ◽  
Tunable Range ◽  
Magnetic Components ◽  
Dielectric Grating

We theoretically and numerically demonstrate a tunable and wide-angle terahertz absorber, which is composed of multilayer graphene-dielectric grating and bottom metal substrate. Numerical simulation shows that the proposed absorber has the advantage of dynamically tunable range from 1.015 THz to 1.165 THz when the chemical potential of graphene increases from 10 meV to 150 meV. The absorption efficiency can reach a high value of 99%. To show the working mechanism of absorption, the near field distributions of magnetic components are presented at the absorption wavelength. We also demonstrate that the tunable range of absorption can be engineered by designing the geometry parameters. In addition, it is shown that the designed absorber can maintain the good performance of absorption over a wide incident angle from [Formula: see text] to [Formula: see text] under TM-polarization.

scholarly journals A Tunable Terahertz Metamaterial Absorber Composed of Hourglass-Shaped Graphene Arrays

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 533 ◽  
Author(s):  
Yunping Qi ◽  
Yu Zhang ◽  
Chuqin Liu ◽  
Ting Zhang ◽  
Baohe Zhang ◽  
...  
Keyword(s):  
Fdtd Method ◽  
Bilayer Graphene ◽  
Metamaterial Absorber ◽  
Dual Band ◽  
Maximum Absorption ◽  
Monolayer Graphene ◽  
Selective Absorption ◽  
Chemical Potentials ◽  
Difference Time ◽  
Absorption Characteristics

In this paper, we demonstrate a tunable periodic hourglass-shaped graphene arrays absorber in the infrared (IR) and terahertz (THz) frequency bands. The effects of graphene geometric parameters, chemical potentials, periods, and incident angles on the pure absorption characteristics are studied by using the Finite Difference Time Domain (FDTD) method. In addition, this paper also analyzes the pure absorption characteristics of bilayer graphene arrays. The simulation results show that the maximum absorption reaches 38.2% for the monolayer graphene structure. Furthermore, comparing the bilayer graphene structure with the monolayer structure under the same conditions shows that the bilayer structure has a tunable dual-band selective absorption effect and has a higher maximum absorption of 41.7%. Moreover, it was found that there are dual-band tunable absorption peaks at 21.6   μ m and 36.3   μ m with the maximum absorption of 41.7% and 11%. The proposed structure is a convenient method which could be used in the design of graphene-based optoelectronic devices, biosensors, and environmental monitors.

scholarly journals Robust Conformal Perfect Absorber Involving Lossy Ultrathin Film

Photonics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 57
Author(s):  
Lei Zhang ◽  
Kun Wang ◽  
Hui Chen ◽  
Yanpeng Zhang
Keyword(s):  
Near Infrared ◽  
Incident Angle ◽  
Broad Band ◽  
Infrared Range ◽  
Subwavelength Structures ◽  
Perfect Absorber ◽  
Perfect Absorption ◽  
Absorption Performance ◽  
Near Infrared Range ◽  
Lossy Material

Perfect absorbers have been extensively investigated due to their significant value in solar cell, photodetection, and stealth technologies. Various subwavelength structures have been proposed to improve the absorption performances, such as high absorptance, broad band, and wide absorption angle. However, excellent performances usually put forward higher requirements on structural designs, such as varying the geometry sizes or shapes to fit different center wavelengths, which inevitably increases the fabrication burden. Here, a planar sandwich structure involving a layer of highly lossy material is proposed to achieve a robust perfect absorption with 95% absorptance ranging from the visible to near infrared range. Such an excellent absorption performance is also polarization-independent and applicable to a wide incident angle. Furthermore, the proposed design can also be applied to conformal surfaces with a 90% fluctuation over a steep surface. We believe that the proposed perfect absorber with distinguished performances can find wide application.

Ultranarrow dual-band metamaterial perfect absorber and its sensing application

2022 ◽  
Author(s):  
Wenhan Zhao ◽  
Junqiao Wang ◽  
Ran Li ◽  
Bin Zhang
Keyword(s):  
Metamaterial Absorber ◽  
Plasmon Mode ◽  
Ring Resonators ◽  
Dual Band ◽  
Storage Device ◽  
Field Pattern ◽  
Perfect Absorber ◽  
Cell Coupling ◽  
Concentric Ring ◽  
Perfect Absorption

Abstract In this paper, a dual-band metamaterial absorber (MMA) with wide-angle and high absorptivity is proposed. The MMA consists of two silver layers separated by a dielectric layer. Its top resonant element is constituted by two concentric ring resonators connected with four strips. Based on electromagnetic field simulation, the proposed MMA has two narrow absorption peaks with an absorption rate of 99.9% at 711 nm and 99.8% at 830 nm, and the corresponding line width of the two absorption peaks are only 9.7 nm and 9.8 nm. The dual-band MMA shows high absorptivity under wide incident angles. The simulated field pattern shows that dual-band perfect absorption is the combined result of the interaction of two concentric ring resonators and unit cell coupling. In addition, the hexapole plasmon mode can be observed at the outer ring at one absorption peak. The narrow plasmon resonance has a potential application in optical sensing, and can be used to measure the concentration of aqueous glucose with two frequency channels. The proposed MMA with high absorptivity is simple to manufacture, and has other potential applications, such as narrow-band filters, energy storage device, and so on.

Wide-band perfect optical absorption and photo-thermal effect for three-tier nanogate

2014 ◽  
Vol 28 (16) ◽  
pp. 1450135
Author(s):  
G. W. Cai ◽  
P. Ding ◽  
J. Q. Wang ◽  
E. J. Liang
Keyword(s):  
Thermal Imaging ◽  
Absorption Rate ◽  
Incident Angle ◽  
Thermal Characteristics ◽  
Wide Band ◽  
Perfect Absorber ◽  
Perfect Absorption ◽  
Cooling Method ◽  
Wide Absorption Band ◽  
Calculation Results

This paper designed a perfect optical absorber based on three-tier gate nanostructure, which shows a wide-band perfect absorption in the wavelength range of 200–560 nm as a transverse wave incidents to the nanostructure with the incident angle 35°< θ< 65°. When θ = 45°, a wide absorption band with the absorption rate more than 94% is observed, with the maximum of absorption rate reaching 99.3% at the wavelength of 430 nm. We also analyze the thermal characteristics of the perfect absorber. The band ranging from 560 nm to 1200 nm presents an increasing absorption rate with the increase of temperature. The calculation results of multi-physics analysis indicate that different cooling method causes different temperature distribution for the perfect absorber. This three-tier gate perfect absorber may find applications on broadband visible detectors, microbolometer and thermal imaging.

scholarly journals An Ultrathin, Triple-Band Metamaterial Absorber with Wide-Incident-Angle Stability for Conformal Applications at X and Ku Frequency Band

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Guangsheng Deng ◽  
Kun Lv ◽  
Hanxiao Sun ◽  
Jun Yang ◽  
Zhiping Yin ◽  
...  
Keyword(s):  
Free Space ◽  
High Efficiency ◽  
Incident Angle ◽  
Surface Current ◽  
Normal Incidence ◽  
Metamaterial Absorber ◽  
Angle Of Incidence ◽  
Perfect Absorption ◽  
Absorption Frequency ◽  
Unit Cells

AbstractAn ultrathin and flexible metamaterial absorber (MA) with triple absorption peaks is presented in this paper. The proposed absorber has been designed in such a way that three absorption peaks are located at 8.5, 13.5, and 17 GHz (X and Ku bands) with absorption of 99.9%, 99.5%, and 99.9%, respectively. The proposed structure is only 0.4 mm thick, which is approximately 1/88, 1/55, and 1/44 for the respective free space wavelengths of absorption frequency in various bands. The MA is also insensitive due to its symmetric geometry. In addition, the proposed structure exhibits minimum 86% absorption (TE incidence) within 60° angle of incidence. For TM incidence, the proposed absorber exhibits more than 99% absorptivity up to 60° incidence. Surface current and electric field distributions were investigated to analyze the mechanism governing absorption. Parameter analyses were performed for absorption optimization. Moreover, the performance of the MA was experimentally demonstrated in free space on a sample under test with 20 × 30 unit cells fabricated on a flexible dielectric. Under normal incidence, the fabricated MA exhibits near perfect absorption at each absorption peak for all polarization angles, and the experimental results were found to be consistent with simulation results. Due to its advantages of high-efficiency absorption over a broad range of incidence angles, the proposed absorber can be used in energy harvesting and electromagnetic shielding.

scholarly journals A wide-angle and TE/TM polarization-insensitive terahertz metamaterial near-perfect absorber based on multi-layer plasmonic structure

2021 ◽  
Author(s):  
Yuanbo Sun ◽  
Yanpeng Shi ◽  
Xiaoyu Liu ◽  
Jinmei Song ◽  
Meiping Li ◽  
...  
Keyword(s):  
Design Method ◽  
Metamaterial Absorber ◽  
Perfect Absorber ◽  
Wide Angle ◽  
Flexible Design ◽  
Plasmonic Structure ◽  
Terahertz Band ◽  
Polarization Insensitive ◽  
Perfect Metamaterial Absorber

A kind of near-perfect metamaterial absorber, made of only Au and Si, has been presented in the terahertz band with extremely high absorptance. A flexible design method is proposed, which...

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