scholarly journals Combined Mie Resonance Metasurface for Wideband Terahertz Absorber

2018 ◽  
Vol 8 (9) ◽  
pp. 1679
Author(s):  
Jie Hu ◽  
Tingting Lang ◽  
Changyu Shen ◽  
Liyang Shao
Keyword(s):  
Electric Fields ◽  
Incident Angle ◽  
Absorption Frequency ◽  
Variable Parameters ◽  
Absorption Bandwidth ◽  
Terahertz Absorber ◽  
Mie Resonance ◽  
Traditional Design ◽  
Single Block ◽  
Application Fields

In this paper, we propose a combined metasurface consisting of an aluminum substrate and an array of TiO2 blocks to achieve a wideband terahertz absorber. We incorporated several similar dielectric blocks with different side length into each unit cell. Each dielectric block could cause magnetic-resonance-inducing absorption effect with different peak wavelengths. Thus, our combined metasurface could achieve wider absorption frequency band than the traditional design when these dielectric blocks were properly designed. The absorption bandwidth could be widened nearly 2.5 times and 5 times compared to a single block case when there were four and nine blocks, respectively, andcouldbe further improved by increasing the number of combinations in structures (variable parameters included number, spacing, dimensions etc.). For both TE00 (the electric fields of the light polarized along the y-axis) and TM00 (the electric fields of the light polarized along the x-axis) polarization states, the absorption bandwidth could be widened effectively; even when the incident angle was 45°, the absorption rate could still reach about 75%. This structure is simple and easy to fabricate, and this design concept can also be used in various other application fields.

scholarly journals Dual-Tunable Broadband Terahertz Absorber Based on a Hybrid Graphene-Dirac Semimetal Structure

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1096
Author(s):  
Jiali Wu ◽  
Xueguang Yuan ◽  
Yangan Zhang ◽  
Xin Yan ◽  
Xia Zhang
Keyword(s):  
Fermi Energy ◽  
Incident Angle ◽  
Normal Incidence ◽  
Surface Conductivity ◽  
Chemical Doping ◽  
Absorption Bandwidth ◽  
Terahertz Absorber ◽  
Dirac Semimetal ◽  
High Absorption ◽  
Broadband Terahertz

A dual-controlled tunable broadband terahertz absorber based on a hybrid graphene-Dirac semimetal structure is designed and studied. Owing to the flexible tunability of the surface conductivity of graphene and relative permittivity of Dirac semimetal, the absorption bandwidth can be tuned independently or jointly by shifting the Fermi energy through chemical doping or applying gate voltage. Under normal incidence, the device exhibits a high absorption larger than 90% over a broad range of 4.06–10.7 THz for both TE and TM polarizations. Moreover, the absorber is insensitive to incident angles, yielding a high absorption over 90% at a large incident angle of 60° and 70° for TE and TM modes, respectively. The structure shows great potential in miniaturized ultra-broadband terahertz absorbers and related applications.

An ultra-wideband, polarization insensitive metamaterial absorber based on multiple resistive film layers with wide-incident-angle stability

2020 ◽  
pp. 1-9
Author(s):  
Guangsheng Deng ◽  
Kun Lv ◽  
Hanxiao Sun ◽  
Yuan Hong ◽  
Xiaoying Zhang ◽  
...  
Keyword(s):  
Incident Angle ◽  
Metamaterial Absorber ◽  
Parameter Analysis ◽  
Ultra Wideband ◽  
High Symmetry ◽  
Large Wave ◽  
Absorption Frequency ◽  
Resistive Film ◽  
Absorption Bandwidth ◽  
Polarization Insensitive

Abstract In this work, we propose a broadband, polarization-insensitive and wide incident angle stable metamaterial absorber (MA) based on the resistive film. The absorber consists of a three-layer structure with each layer of dielectric substrate printed with different shapes of resistive film. The multilayer structure not only extends the absorption bandwidth but also maintains high absorption under large wave incident angles. Numerical simulation shows that the absorptivity of a normal incident wave is above 90% in the frequency range 2.34–18.95 GHz, corresponding to a relative absorption bandwidth of 156%. Moreover, the whole MA structure has a total thickness of 11.3 mm, corresponding to 0.09 λ0 at its lowest absorption frequency. Due to the high symmetry of the structure, the absorber has good polarization insensitivity. In addition, for both transverse electric and transverse magnetic incidence, the proposed absorber achieves an absorptivity of more than 80% at incident angles of up to 45° and thus has good stability for wide incident angles. The absorption principle of the absorber is analyzed by the surface current and power loss density distribution. Parameter analysis is also performed for bandwidth optimization. Due to its advantages of wideband absorption with high efficiency, the proposed absorber has the potential to be applied to the energy-harvesting and electromagnetic stealth fields.

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 Wideband terahertz absorber based on Mie resonance metasurface

AIP Advances ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 115310 ◽  
Author(s):  
Qingmin Wang ◽  
Ruilin Zhou ◽  
Xuying Wang ◽  
Yunsheng Guo ◽  
Yanan Hao ◽  
...  
Keyword(s):  
Terahertz Absorber ◽  
Mie Resonance

A bi-directional dual-bandwidth microwave absorber for applications in X and Ku bands

2019 ◽  
Vol 11 (9) ◽  
pp. 983-987
Author(s):  
Gobinda Sen ◽  
Santanu Das
Keyword(s):  
Electromagnetic Wave ◽  
Incident Angle ◽  
Microwave Absorber ◽  
Wave Incident ◽  
Absorption Bandwidth ◽  
Radar Absorbing Material ◽  
Ring Shape ◽  
Band Absorption ◽  
Dual Bandwidth ◽  
5 Ghz

AbstractThis paper presents a microwave absorber with dual absorption bandwidth response based upon the direction of electromagnetic wave incident on the surface. The design unit cell comprises a staircase shape metallic patch on the top plane and an array of 2×2 meander square ring shape dual layer frequency selective surfaces (FSS) in the middle and bottom planes. The relative absorption bandwidth (RAB) of 39.40% (5 GHz) with more than 90% absorption of incident wave power is achieved when an electromagnetic wave impinges normally on the top plane making it suitable for wideband applications in the X and Ku bands. For the wave incident normally on the bottom plane, the same structure gives narrow band absorption with an RAB of 2.29% (260 MHz) for more than 90% absorption around 11 GHz. Thus, this bi-directional ability of the proposed design is found to be suitable for radar absorbing material, multi-bandwidth, and diverse applications. The absorption performance is also studied for different values of incident angle. The distribution of surface currents on the staircase patch and on the two FSS layers at resonant frequencies of 11 GHz and 14 GHz is analyzed to elaborate the absorption phenomenon physically. The prototype of this design is fabricated and the experimental results are found to be closely following the simulated one.

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 Design of broadband metamaterial-based ferromagnetic absorber

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Yan Shi 1 ◽  
Jie Yang 1 ◽  
Hua Shen 1 ◽  
Zhankui Meng 1 ◽  
Tong Hao 1
Keyword(s):  
Incident Angle ◽  
Single Layer ◽  
Resonant Absorption ◽  
Periodic Array ◽  
Ferromagnetic Property ◽  
Microwave Frequencies ◽  
Absorption Bandwidth ◽  
Symmetric Structure ◽  
Polarization Insensitive ◽  
Absorption Mode

In this paper, a metamaterial-based ferromagnetic absorber has been designed at microwave frequencies. The proposed absorber is composed of a periodic array of stacked circular ferromagnetic patches fabricated on the FR4 substrate. With the ferromagnetic property, the single-layer patch array generates a good resonant absorption mode. By stacking multiple ferromagnetic patches, the designed absorber with the absorption above 90% has a wide absorption bandwidth from 10 to 21 GHz. Due to the symmetric structure, the proposed absorber is polarization insensitive. At oblique incident with the incident angle of 45o, the good absorption more than 80% can be achieved in the whole operation band.

scholarly journals Experimental realization of Mie-resonance terahertz absorber by self-assembly method

2018 ◽  
Vol 26 (10) ◽  
pp. 13001 ◽  
Author(s):  
Jiannan Gao ◽  
Chuwen Lan ◽  
Qian Zhao ◽  
Bo Li ◽  
Ji Zhou
Keyword(s):  
Self Assembly ◽  
Experimental Realization ◽  
Terahertz Absorber ◽  
Assembly Method ◽  
Mie Resonance

Ultra-narrowband mid-infrared absorber based on Mie resonance in dielectric metamaterials

2020 ◽  
Vol 98 (5) ◽  
pp. 484-487 ◽  
Author(s):  
Yan-Lin Liao ◽  
Yan Zhao
Keyword(s):  
Magnetic Field ◽  
Absorption Rate ◽  
Resonance Wavelength ◽  
Mid Infrared ◽  
Absorption Bandwidth ◽  
Mie Resonance ◽  
Thermal Emitter ◽  
Simulation Results ◽  
Simulated Field ◽  
High Absorption

Ultra-narrowband absorbers can be applied in many applications. We propose a mid-infrared ultra-narrowband absorber with TM polarization (magnetic field is parallel to grating grooves) based on dielectric metamaterials in this paper. The simulation results show that the absorption rate larger than 0.99 can be achieved at the resonance wavelength, and the absorption bandwidth is less than 10 nm. The simulated field distribution shows that the ultra-narrowband absorption in this absorber originates from Mie resonance. In addition, the absorber preserves high absorption rates up to 4° which means that our absorber has high directivity. Our results show that the ultra-narrowband absorbers can be applied as a thermal emitter.

scholarly journals Polarization-Insensitive Broadband THz Absorber Based on Circular Graphene Patches

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2709
Author(s):  
Jiajia Qian ◽  
Jun Zhou ◽  
Zheng Zhu ◽  
Zhenzhen Ge ◽  
Shuting Wu ◽  
...  
Keyword(s):  
Incident Angle ◽  
Structural Parameters ◽  
Single Layer Graphene ◽  
Localized Surface Plasmon ◽  
Wide Angle ◽  
Absorption Bandwidth ◽  
Broadband Absorption ◽  
Simulation And Optimization ◽  
Symmetrical Configuration ◽  
Polarization Insensitive

A polarization-insensitive broadband terahertz absorber based on single-layer graphene metasurface has been designed and simulated, in which the graphene metasurface is composed of isolated circular patches. After simulation and optimization, the absorption bandwidth of this absorber with more than 90% absorptance is up to 2 THz. The simulation results demonstrate that the broadband absorption can be achieved by combining the localized surface plasmon (LSP) resonances on the graphene patches and the resonances caused by the coupling between them. The absorption bandwidth can be changed by changing the chemical potential of graphene and the structural parameters. Due to the symmetrical configuration, the proposed absorber is completely insensitive to polarization and have the characteristics of wide angle oblique incidence that they can achieve broadband absorption with 70% absorptance in the range of incident angle from 0° to 50° for both TE and TM polarized waves. The flexible and simple design, polarization insensitive, wide-angle incident, broadband and high absorption properties make it possible for our proposed absorber to have promising applications in terahertz detection, imaging and cloaking objects.

Sign in / Sign up

Export Citation Format

Share Document