scholarly journals A Narrow Dual-Band Monolayer Unpatterned Graphene-Based Perfect Absorber with Critical Coupling in the Near Infrared

Micromachines ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 58 ◽  
Author(s):  
Pinghui Wu ◽  
Zeqiang Chen ◽  
Danyang Xu ◽  
Congfen Zhang ◽  
Ronghua Jian
Keyword(s):  
Optical Switching ◽  
Near Infrared ◽  
High Efficiency ◽  
Dual Band ◽  
Resonance Structure ◽  
Perfect Absorber ◽  
Critical Coupling ◽  
Infrared Band ◽  
Guided Mode ◽  
The Cross

The combination of critical coupling and coupled mode theory in this study elevated the absorption performance of a graphene-based absorber in the near-infrared band, achieving perfect absorption in the double bands (98.96% and 98.22%), owing to the guided mode resonance (the coupling of the leak mode and guided mode under the condition of phase matching, which revealed 100% transmission or reflection efficiency in the wavelet band), and a third high-efficiency absorption (91.34%) emerged. During the evaluation of the single-structure, cross-circle-shaped absorber via simulation and theoretical analysis, the cross-circle shaped absorber assumed a conspicuous preponderance through exploring the correlation between absorption and tunable parameters (period, geometric measure, and incident angle of the cross-circle absorber), and by briefly analyzing the quality factors and universal applicability. Hence, the cross-circle resonance structure provides novel potential for the design of a dual-band unpatterned graphene perfect absorber in the near-infrared band, and possesses practical application significance in photoelectric detectors, modulators, optical switching, and numerous other photoelectric devices.

scholarly journals Perfect Dual-Band Absorber Based on Plasmonic Effect with the Cross-Hair/Nanorod Combination

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 493 ◽  
Author(s):  
Yuan-Fong Chou Chau ◽  
Chung-Ting Chou Chao ◽  
Hung Ji Huang ◽  
Muhammad Raziq Rahimi Kooh ◽  
N. T. R. N. Kumara ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Near Infrared ◽  
High Sensitivity ◽  
Dual Band ◽  
Localized Surface Plasmon ◽  
Perfect Absorber ◽  
Plasmonic Effect ◽  
Plasmonic Sensor ◽  
Nanophotonic Devices ◽  
The Cross

Plasmonic effect using a cross-hair can convey strongly localized surface plasmon modes among the separated composite nanostructures. Compared to its counterpart without the cross-hair, this characteristic has the remarkable merit of enhancing absorptance at resonance and can make the structure carry out a dual-band plasmonic perfect absorber (PPA). In this paper, we propose and design a novel dual-band PPA with a gathering of four metal-shell nanorods using a cross-hair operating at visible and near-infrared regions. Two absorptance peaks at 1050 nm and 750 nm with maximal absorptance of 99.59% and 99.89% for modes 1 and 2, respectively, are detected. High sensitivity of 1200 nm refractive unit (1/RIU), figure of merit of 26.67 and Q factor of 23.33 are acquired, which are very remarkable compared with the other PPAs. In addition, the absorptance in mode 1 is about nine times compared to its counterpart without the cross-hair. The proposed structure gives a novel inspiration for the design of a tunable dual-band PPA, which can be exploited for plasmonic sensor and other nanophotonic devices.

scholarly journals Giant dual-band asymmetric transmission based on all-dielectric metamaterial in the near-infrared band

2021 ◽  
Author(s):  
BingYu Chen ◽  
Kun Zhang ◽  
Qun Xie ◽  
Xingrun Zhang ◽  
Lijun Guo ◽  
...  
Keyword(s):  
Near Infrared ◽  
Dual Band ◽  
Infrared Band ◽  
Asymmetric Transmission

scholarly journals Ultra Narrow Dual-Band Perfect Absorber Based on a Dielectric−Dielectric−Metal Three-Layer Film Material

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1552
Author(s):  
Bin Liu ◽  
Pinghui Wu ◽  
Hongyang Zhu ◽  
Li Lv
Keyword(s):  
Plasmon Resonance ◽  
Near Infrared ◽  
Incident Angle ◽  
Structural Parameters ◽  
Dual Band ◽  
Refractive Index Sensor ◽  
Perfect Absorber ◽  
Film Material ◽  
High Q ◽  
Magnetic Polaritons

This paper proposes a perfect metamaterial absorber based on a dielectric−dielectric−metal structure, which realizes ultra-narrowband dual-band absorption in the near-infrared band. The maximum Q factor is 484. The physical mechanism that causes resonance is hybrid coupling between magnetic polaritons resonance and plasmon resonance. At the same time, the research results show that the intensity of magnetic polaritons resonance is much greater than the intensity of the plasmon resonance. By changing the structural parameters and the incident angle of the light source, it is proven that the absorber is tunable, and the working angle tolerance is 15°. In addition, the sensitivity and figure of merit when used as a refractive index sensor are also analyzed. This design provides a new idea for the design of high-Q optical devices, which can be applied to photon detection, spectral sensing, and other high-Q multispectral fields.

scholarly journals High Quality Factor, High Sensitivity Metamaterial Graphene—Perfect Absorber Based on Critical Coupling Theory and Impedance Matching

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 95 ◽  
Author(s):  
Chunlian Cen ◽  
Zeqiang Chen ◽  
Danyang Xu ◽  
Liying Jiang ◽  
Xifang Chen ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Quality Factor ◽  
Near Infrared ◽  
Coupling Effect ◽  
Impedance Matching ◽  
High Quality Factor ◽  
Monolayer Graphene ◽  
Perfect Absorber ◽  
Critical Coupling ◽  
High Quality

By means of critical coupling and impedance matching theory, we have numerically simulated the perfect absorption of monolayer graphene. Through the critical coupling effect and impedance matching, we studied a perfect single-band absorption of the monolayer graphene and obtained high quality factor (Q-factor = 664.2) absorption spectrum which has an absorbance close to 100% in the near infrared region. The position of the absorption spectrum can be adjusted by changing the ratio between the radii of the elliptic cylinder air hole and the structural period. The sensitivity of the absorber can be achieved S = 342.7 nm/RIU (RIU is the per refractive index unit) and FOM = 199.2 (FOM is the figure of merit), which has great potential for development on biosensors. We believe that our research will have good application prospects in graphene photonic devices and optoelectronic devices.

scholarly journals A Tunable Dual-Band and Polarization-Insensitive Coherent Perfect Absorber Based on Double-Layers Graphene Hybrid Waveguide

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Xin Luo ◽  
Zi-Qiang Cheng ◽  
Xiang Zhai ◽  
Zhi-Min Liu ◽  
Si-Qi Li ◽  
...  
Keyword(s):  
Wide Spectrum ◽  
Dual Band ◽  
Double Layers ◽  
Monolayer Graphene ◽  
Perfect Absorber ◽  
Infrared Band ◽  
Perfect Absorption ◽  
Mid Infrared ◽  
Polarization Insensitive ◽  
Coherent Perfect Absorber

Abstract A suspended monolayer graphene has only about 2.3% absorption rate in visible and infrared band, which limits its optoelectronic applications. To significantly increase graphene’s absorption efficiency, a tunable dual-band and polarization-insensitive coherent perfect absorber (CPA) is proposed in the mid-infrared regime, which contains the silicon array coupled in double-layers graphene waveguide. Based on the FDTD methods, dual-band perfect absorption peaks are achieved in 9611 nm and 9924 nm, respectively. Moreover, due to its center symmetric feature, the proposed absorber also demonstrates polarization-insensitive. Meanwhile, the coherent absorption peaks can be all-optically modulated by altering the relative phase between two reverse incident lights. Furthermore, by manipulating the Fermi energies of two graphene layers, two coherent absorption peaks can move over a wide spectrum range, and our designed CPA can also be changed from dual-band CPA to narrowband CPA. Thus, our results can find some potential applications in the field of developing nanophotonic devices with excellent performance working at the mid-infrared regime.

Dual-band near-infrared plasmonic perfect absorber assisted by strong coupling between bright-dark nanoresonators

2016 ◽  
Vol 380 ◽  
pp. 267-272 ◽  
Author(s):  
Yudong Lian ◽  
Guobin Ren ◽  
Huaiqing Liu ◽  
Yixiao Gao ◽  
Bofeng Zhu ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Near Infrared ◽  
Dual Band ◽  
Perfect Absorber

scholarly journals An Ultrahigh Narrowband Absorber Close to the Information Communication Window

2021 ◽  
Author(s):  
Wajid Ali ◽  
Shahid Iqbal ◽  
Muhib Ullah ◽  
Xiaoli Wang
Keyword(s):  
Optical Switching ◽  
Near Infrared ◽  
Transverse Electric ◽  
Electromagnetic Spectrum ◽  
Perfect Absorber ◽  
Synergy Effect ◽  
Information Communication ◽  
Absorption Properties ◽  
Wide Range ◽  
All Optical

Abstract In this paper, we demonstrate a plasmonic ultrahigh narrowband perfect absorber, which realizes an absorption intensity of up to 99.99% in the near-infrared electromagnetic spectrum regime. Different dimensional effects on absorption properties are studied using computer simulation technology (CST) with finite element method (FEM) solver. For both transverse electric (TE) and magnetic (TM) polarization, the absorber shows high stability over a wide range of incident angles. This ultrahigh absorption is attributed to synergy effect of magnetic resonance and surface plasmon resonance. Furthermore, the sensitivity goes to 300 nm/RIU for various refractive indices of different analytes. Our proposed absorber working wavelength is very close to the communication window of information, therefore, except for remarkable sensing abilities, it can also be well utilized in optoelectronic applications like optical switching, amplifiers, and all-optical plasmonic modulators.

scholarly journals High-Efficiency Responsive Smart Windows Fabricated by Carbon Nanotubes Modified by Liquid Crystalline Polymers

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 440
Author(s):  
Yuan Deng ◽  
Shi-Qin Li ◽  
Qian Yang ◽  
Zhi-Wang Luo ◽  
He-Lou Xie
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystalline ◽  
Near Infrared ◽  
High Efficiency ◽  
Polymer Brush ◽  
Light Transmittance ◽  
Smart Window ◽  
Vertical Orientation ◽  
Smart Windows ◽  
Conversion Materials

Smart windows can dynamically and adaptively adjust the light transmittance in non-energy or low-energy ways to maintain a comfortable ambient temperature, which are conducive to efficient use of energy. This work proposes a liquid crystal (LC) smart window with highly efficient near-infrared (NIR) response using carbon nanotubes grafted by biphenyl LC polymer brush (CNT-PDB) as the orientation layer. The resultant CNT-PDB polymer brush can provide the vertical orientation of LC molecules to maintain the initial transparency. At the same time, the smart window shows a rapid response to NIR light, which can quickly adjust the light transmittance to prevent sunlight from entering the room. Different from common doping systems, this method avoids the problem of poor compatibility between the LC host and photothermal conversion materials, which is beneficial for improving the durability of the device.

scholarly journals High-Efficiency, Dual-Band Beam Splitter Based on an All-Dielectric Quasi-Continuous Metasurface

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3184
Author(s):  
Jing Li ◽  
Yonggang He ◽  
Han Ye ◽  
Tiesheng Wu ◽  
Yumin Liu ◽  
...  
Keyword(s):  
Wavelength Range ◽  
Conversion Efficiency ◽  
Antenna Arrays ◽  
Beam Splitter ◽  
High Efficiency ◽  
Visible Region ◽  
Polarized Light ◽  
Dual Band ◽  
Phase Gradient ◽  
Total Transmission

Metasurface-based beam splitters attracted huge interest for their superior properties compared with conventional ones made of bulk materials. The previously reported designs adopted discrete metasurfaces with the limitation of a discontinuous phase profile. In this paper, we propose a dual-band beam splitter, based on an anisotropic quasi-continuous metasurface, by exploring the optical responses under x-polarized (with an electric field parallel to the direction of the phase gradient) and y-polarized incidences. The adopted metasurface consists of two identical trapezoidal silicon antenna arrays with opposite spatial variations that lead to opposite phase gradients. The operational window of the proposed beam splitter falls in the infrared and visible region, respectively, for x- and y-polarized light, resulting from the different mechanisms. When x-polarized light is incident, the conversion efficiency and total transmission of the beam splitter remains higher than 90% and 0.74 within the wavelength range from 969 nm to 1054 nm, respectively. In this condition, each array can act as a beam splitter of unequal power. For y-polarized incidence, the maximum conversion efficiency and transmission reach approximately 100% and 0.85, while the values remain higher than 90% and 0.65 in the wavelength range from 687 nm to 710 nm, respectively. In this case, each array can be viewed as an effective beam deflector. We anticipate that it can play a key role in future integrated optical devices.

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