Metamaterial for polarization-incident angle independent broadband perfect absorption in the terahertz range

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.

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

Journal of Physics Conference Series ◽

10.1088/1742-6596/2109/1/012015 ◽

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.

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Wideband tunable perfect absorption of graphene plasmons via attenuated total reflection in Otto prism configuration

Nanophotonics ◽

10.1515/nanoph-2019-0400 ◽

2020 ◽

Vol 9 (3) ◽

pp. 645-655 ◽

Cited By ~ 3

Author(s):

Jinpeng Nong ◽

Linlong Tang ◽

Guilian Lan ◽

Peng Luo ◽

Caicheng Guo ◽

...

Keyword(s):

Graphene Nanoribbons ◽

Incident Angle ◽

Evanescent Waves ◽

Attenuated Total Reflection ◽

Absorption Properties ◽

Perfect Absorption ◽

Dielectric Spacer ◽

Graphene Plasmons ◽

Localized Plasmons ◽

Effective Degree

AbstractA strategy is proposed to achieve wideband tunable perfect plasmonic absorption in graphene nanoribbons by employing attenuated total refraction (ATR) in Otto prism configuration. In this configuration, the Otto prism with a deep-subwavelength dielectric spacer is used to generate tunneling evanescent waves to excite localized plasmons in graphene nanoribbons. The influence of the configuration parameters on the absorption spectra of graphene plasmons is studied systematically, and the key finding is that perfect absorption can be achieved by actively controlling the incident angle of light under ATR conditions, which provides an effective degree of freedom to tune the absorption properties of graphene plasmons. Based on this result, it is further demonstrated that by simultaneously tuning the incident angle and the graphene Fermi energy, the tunable absorption waveband can be significantly enlarged, which is about 3 times wider than the conventional cavity-enhanced configuration. Our proposed strategy to achieve wideband, tunable graphene plasmons could be useful in various infrared plasmonic devices.

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Robust Conformal Perfect Absorber Involving Lossy Ultrathin Film

Photonics ◽

10.3390/photonics7030057 ◽

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.

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

Modern Physics Letters B ◽

10.1142/s0217984914501358 ◽

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.

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

Nanoscale Research Letters ◽

10.1186/s11671-020-03448-0 ◽

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.

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Si Substrate-Based Metamaterials for Ultrabroadband Perfect Absorption in Visible Regime

Journal of Nanomaterials ◽

10.1155/2014/893202 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Qi Han ◽

Lei Jin ◽

Yongqi Fu ◽

Weixing Yu

Keyword(s):

Incident Angle ◽

Si Substrate ◽

Perfect Absorption ◽

Photonic Circuits ◽

Si Photonics ◽

Fabry Perot ◽

Absorbing Property ◽

Photonics Devices

We report the broadband efficient light absorbing property of a structure of quadrangular frustum pyramid array in visible regime. The structure can absorb light efficiently with an average absorptivity of 0.98 over the whole visible waveband. In addition, it is found that this kind of super light absorbing can maintain an average of 0.9 for a wide incident angle range. The perfect absorbing property of the metamaterial-based nanoring array is attributed to the effect of the Fabry-Perot resonance. The structure is possible to be used as a type of Si photonics devices in future photonic circuits.

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A new compact dual-band perfect absorption ultrathin planar metasurface energy harvester in X- and V-bands with a wide incident angle

AIP Advances ◽

10.1063/5.0012857 ◽

2020 ◽

Vol 10 (8) ◽

pp. 085007 ◽

Cited By ~ 1

Author(s):

Alireza Ghaneizadeh ◽

Khalil Mafinezhad ◽

Mojtaba Joodaki

Keyword(s):

Energy Harvester ◽

Incident Angle ◽

Dual Band ◽

Perfect Absorption

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Towards Perfect Absorption of Single Layer CVD Graphene in an Optical Resonant Cavity: Challenges and Experimental Achievements

Materials ◽

10.3390/ma15010352 ◽

2022 ◽

Vol 15 (1) ◽

pp. 352

Author(s):

Abedin Nematpour ◽

Maria Luisa Grilli ◽

Laura Lancellotti ◽

Nicola Lisi

Keyword(s):

Incident Angle ◽

Resonant Cavity ◽

Experimental Studies ◽

Single Layer ◽

Absorption Enhancement ◽

Perfect Absorption ◽

Cvd Graphene ◽

Graphene Layers ◽

Absorption Increase ◽

Fabry Perot

Graphene is emerging as a promising material for the integration in the most common Si platform, capable to convey some of its unique properties to fabricate novel photonic and optoelectronic devices. For many real functions and devices however, graphene absorption is too low and must be enhanced. Among strategies, the use of an optical resonant cavity was recently proposed, and graphene absorption enhancement was demonstrated, both, by theoretical and experimental studies. This paper summarizes our recent progress in graphene absorption enhancement by means of Si/SiO2-based Fabry–Perot filters fabricated by radiofrequency sputtering. Simulations and experimental achievements carried out during more than two years of investigations are reported here, detailing the technical expedients that were necessary to increase the single layer CVD graphene absorption first to 39% and then up to 84%. Graphene absorption increased when an asymmetric Fabry–Perot filter was applied rather than a symmetric one, and a further absorption increase was obtained when graphene was embedded in a reflective rather than a transmissive Fabry–Perot filter. Moreover, the effect of the incident angle of the electromagnetic radiation and of the polarization of the light was investigated in the case of the optimized reflective Fabry–Perot filter. Experimental challenges and precautions to avoid evaporation or sputtering induced damage on the graphene layers are described as well, disclosing some experimental procedures that may help other researchers to embed graphene inside PVD grown materials with minimal alterations.

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A Perfect Absorber Based on Similar Fabry-Perot Four-Band in the Visible Range

Nanomaterials ◽

10.3390/nano10030488 ◽

2020 ◽

Vol 10 (3) ◽

pp. 488 ◽

Cited By ~ 11

Author(s):

Pinghui Wu ◽

Congfen Zhang ◽

Yijun Tang ◽

Bin Liu ◽

Li Lv

Keyword(s):

Near Infrared ◽

Layer Structure ◽

Incident Angle ◽

Middle Layer ◽

Absorption Efficiency ◽

Visible Range ◽

Polarization Angle ◽

Perfect Absorber ◽

Perfect Absorption ◽

Fabry Perot

A simple metamaterial absorber is proposed to achieve near-perfect absorption in visible and near-infrared wavelengths. The absorber is composed of metal-dielectric-metal (MIM) three-layer structure. The materials of these three-layer structures are Au, SiO2, and Au. The top metal structure of the absorber is composed of hollow three-dimensional metal rings regularly arranged periodically. The results show that the high absorption efficiency at a specific wavelength is mainly due to the resonance of the Fabry–Perot effect (FP) in the intermediate layer of the dielectric medium, resulting in the resonance light being trapped in the middle layer, thus improving the absorption efficiency. The almost perfect multiband absorption, which is independent of polarization angle and insensitivity of incident angle, lends the absorber great application prospects for filtering and optoelectronics.

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