Polarization-Insensitive Broadband THz Absorber Based on Circular Graphene Patches

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.

Download Full-text

Electrically Tunable Broadband Terahertz Absorption with Hybrid-Patterned Graphene Metasurfaces

Nanomaterials ◽

10.3390/nano8080562 ◽

2018 ◽

Vol 8 (8) ◽

pp. 562 ◽

Cited By ~ 20

Author(s):

Longfang Ye ◽

Xin Chen ◽

Guoxiong Cai ◽

Jinfeng Zhu ◽

Na Liu ◽

...

Keyword(s):

Incident Angle ◽

Single Layer ◽

Normal Incidence ◽

Transverse Magnetic ◽

Single Layer Graphene ◽

Terahertz Waves ◽

Broadband Absorption ◽

Terahertz Sensing ◽

Axisymmetric Configuration ◽

Broadband Terahertz

We numerically demonstrate a broadband terahertz (THz) absorber that is based on a hybrid-patterned graphene metasurface with excellent properties of polarization insensitivity, wide-angle, and active tunability. Our design is made up of a single-layer graphene with periodically arranged hybrid square/disk/loop patterns on a multilayer structure. We find that broadband absorption with 90% terahertz absorbance and the fractional bandwidth of 84.5% from 1.38 THz to 3.4 THz can be achieved. Because of the axisymmetric configuration, the absorber demonstrates absolute polarization independence for both transverse electric (TE) and transverse magnetic (TM) polarized terahertz waves under normal incidence. We also show that a bandwidth of 60% absorbance still remains 2.7 THz, ranging from 1.3 THz to 4 THz, for a wide incident angle ranging from 0° to 60°. Finally, we find that by changing the graphene Fermi energy from 0.7 eV to 0 eV, the absorbance of the absorbers can be easily tuned from more than 90% to lower than 20%. The proposed absorber may have promising applications in terahertz sensing, detecting, imaging, and cloaking.

Download Full-text

Polarization-insensitive and wide-angle broadband absorption enhancement of molybdenum disulfide in visible regime

Optics Express ◽

10.1364/oe.26.033918 ◽

2018 ◽

Vol 26 (26) ◽

pp. 33918 ◽

Cited By ~ 25

Author(s):

Xin Luo ◽

Zhimin Liu ◽

Ziqiang Cheng ◽

Jianping Liu ◽

Qi Lin ◽

...

Keyword(s):

Molybdenum Disulfide ◽

Absorption Enhancement ◽

Wide Angle ◽

Broadband Absorption ◽

Polarization Insensitive

Download Full-text

Cascaded Nanorod Arrays for Ultrabroadband, Omnidirectional and Polarization-Insensitive Absorption

Applied Sciences ◽

10.3390/app10113878 ◽

2020 ◽

Vol 10 (11) ◽

pp. 3878

Author(s):

Xun Wang ◽

Tian Sang ◽

Honglong Qi ◽

Guoqing Li ◽

Xin Yin ◽

...

Keyword(s):

Wavelength Range ◽

Near Infrared ◽

Structural Parameters ◽

Resonant Cavity ◽

Dielectric Materials ◽

Localized Surface Plasmon ◽

Nanorod Arrays ◽

Absorption Properties ◽

Polarization Insensitive ◽

Absorption Performance

An ultrabroadband, omnidirectional, and polarization-insensitive absorber based on cascaded nanorod arrays (CNAs) is numerically demonstrated, and an average absorptivity of 98.2% with a relative absorption bandwidth (RAB) of 149.8% can be achieved in the 0.38–2.65 μm wavelength range. The proposed CNA-based absorber requires only several pairs of multilayers to achieve excellent absorption performance. More significantly, the physical mechanism for this intriguing ultrabroadband absorption results from the synergistic effect of localized surface plasmon (LSP) and plasmonic resonant cavity (PRC) modes, which is fundamentally different from the tapered metal/dielectric multilayer-based absorbers associated with the slow-light mode. We investigated the absorption properties of the CNA-based metasurface by using the impedance theory, which indicates that the impedance of the structure matches well with the impedance of the free space from the visible to near-infrared wavelength range. In addition, the absorption properties of the CNA-based metasurface are robust to the variation of the structural parameters and the metal/dielectric materials, and ultrabroadband absorption performance can be maintained within 0–60° for both TM and TE modes.

Download Full-text

A Photoexcited Broadband Absorption Based on Au Nano Cross Elliptical Disks Structure with Polarization-Insensitive and Wide-Angle for Visible Light

Plasmonics ◽

10.1007/s11468-016-0244-z ◽

2016 ◽

Vol 12 (1) ◽

pp. 165-170

Author(s):

Xiuli Jia ◽

Xiaoou Wang ◽

Zhongxiang Zhou ◽

Qingxin Meng

Keyword(s):

Visible Light ◽

Wide Angle ◽

Broadband Absorption ◽

Polarization Insensitive

Download Full-text

Design of broadband metamaterial-based ferromagnetic absorber

Materials Science Advanced Composite Materials ◽

10.18063/msacm.v2i3.736 ◽

2018 ◽

Vol 2 (2) ◽

Cited By ~ 3

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.

Download Full-text

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

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078720000513 ◽

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.

Download Full-text