scholarly journals A Designed Broadband Absorber Based on ENZ Mode Incorporating Plasmonic Metasurfaces

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 673 ◽  
Author(s):  
Dang ◽  
Le ◽  
Lee ◽  
Nguyen
Keyword(s):  
Numerical Study ◽  
Metal Structure ◽  
Infrared Region ◽  
Transverse Magnetic ◽  
Metamaterial Absorber ◽  
Light Illumination ◽  
Broadband Absorber ◽  
Practical Applications ◽  
Solar Energy Harvesting ◽  
Wide Range

In this paper, we present a numerical study of a metamaterial absorber that provides polarization-insensitive absorption over a broad bandwidth of operation over the mid-infrared region. The absorber consists of a periodically patterned metal-dielectric-metal structure integrated with an epsilon-near-zero (ENZ) nanolayer into the insulating dielectric gap region. Such an anomalous broadband absorber is achieved thanks to a couple of resonant modes including plasmon and ENZ modes that are excited under mid-IR light illumination. By adding a 0.06-μm-thick ENZ layer between the patterned gold rectangular grating and the SiO2 dielectric layer, the absorber captures >95% light over a 1.5 µm bandwidth centered at a near-8-μm wavelength over a wide range of oblique incidence under transverse-magnetic and -electric polarizations. The designed ENZ-based wideband absorber has potential for many practical applications, including sensing, imaging and solar energy harvesting over a wide frequency regime.

scholarly journals Broadband microwave metamaterial absorber with lumped resistor loading

2019 ◽  
Vol 6 ◽  
pp. 1 ◽  
Author(s):  
Ke Chen ◽  
Xinyao Luo ◽  
Guowen Ding ◽  
Junming Zhao ◽  
Yijun Feng ◽  
...  
Keyword(s):  
Electromagnetic Compatibility ◽  
Design Principle ◽  
Transverse Electric ◽  
Transverse Magnetic ◽  
Metamaterial Absorber ◽  
Absorption Bandwidth ◽  
Practical Applications ◽  
Angular Performance ◽  
Polarization Insensitive ◽  
Metamaterial Absorbers

Narrow absorption bandwidth has been a fundamental drawback hindering many metamaterial absorbers for practical applications. In this paper, by loading lumped resistors, we have successfully designed a microwave metamaterial absorber with multioctave wide absorption bandwidth covering the entire X- and Ku-bands, while keeping the thickness of the absorber less than 1/10 of the working wavelength. The polarization-insensitive absorber shows a good angular stability for both transverse electric (TE) and transverse magnetic (TM) incidences. Prototype has been fabricated and measured to validate the design principle and the simulated results, and good agreements are observed between simulated and measured results. The proposed metamaterial absorber offers an efficient way to realize broadband microwave absorption with stable angular performance, which may find potential uses in many applications, for example, electromagnetic compatibility.

Transmittance and Absorption Properties of Graphene Multilayer Quasi-periodic Structure: Period-Doubling case

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2781-2786 ◽  
Author(s):  
C. Sifuentes-Gallardo ◽  
I. A. Sustaita-Torres ◽  
I. Rodríguez-Vargas ◽  
J. R. Suárez-López ◽  
J. Madrigal-Melchor
Keyword(s):  
Strong Dependence ◽  
Period Doubling ◽  
Optical Filters ◽  
Infrared Region ◽  
Transverse Magnetic ◽  
Storage Device ◽  
Absorption Properties ◽  
Wide Range ◽  
Potential Applications ◽  
Transmission And Absorption

ABSTRACTGraphene is a two dimensional material of special interest due to its unusual electronic, mechanical, chemical, optical among other properties, which suggest a wide range of applications in optoelectronics, computer, ecology, etc. The study of the optical properties of graphene is important due to its potential applications such as ultrafast photonics, optical filters, composite materials, photovoltaics and energy storage device. In this work we study the transmission and absorption properties of a quasi-regular multilayer dielectric-graphene-dielectric system. The multilayer structure is built on the quasi-regular Period-Doubling (PD) sequence. The optical response of graphene takes into account intra-band and inter-band transitions. We use the transfer-matrix method to calculate the transmission and absorption spectra. It is obtained a strong dependence on the number of layers in the system, the width of dielectric media and the optical contrast. Furthermore, we calculate the spectra for both transverse magnetic (TM) and transverse electric (TE) polarization in the infrared region.

Design of an ultrabroadband visible metamaterial absorber based on three-dimensional metallic nanostructures

2017 ◽  
Vol 31 (25) ◽  
pp. 1750231 ◽  
Author(s):  
Hao Luo ◽  
Yong Zhi Cheng
Keyword(s):  
Thermal Imaging ◽  
Three Dimensional ◽  
Metamaterial Absorber ◽  
Optimized Design ◽  
Solar Energy Harvesting ◽  
Relative Bandwidth ◽  
Wide Range ◽  
Polarization Insensitive ◽  
Simulation Results ◽  
Energy Harvesting Devices

We present the design and numerical simulations of an ultrabroadband visible metamaterial absorber (MMA) with polarization-insensitive and wide-angle based on three-dimensional (3D) metallic nanostructure. Distinct from previous designs, the proposed visible MMA only consisted of structured 3D metallic film constructed with an assembly of four vertical split-rings (FVSR) structure. For the optimized design of our MMA, the absorbance of over 90% with a relative bandwidth of 94.8% can be obtained. Further simulation results indicate that our design is polarization-insensitive and also operated well in a wide range of incident angles for both TE and TM modes. In addition, the designed visible MMA design can tolerate some geometric parameters errors in fabrication. Thus, the proposed visible MMA can be potential application in the photodetectors, thermal imaging, photoelectrochemical, and solar energy harvesting devices.

A New Detector System For The HB5 Stem Instrument

1985 ◽  
Vol 43 ◽  
pp. 134-135
Author(s):  
J.M. Cowley
Keyword(s):  
Dark Field ◽  
Detector System ◽  
Electron Holography ◽  
Small Specimen ◽  
Bright Field ◽  
Multiple Images ◽  
Practical Applications ◽  
Wide Range ◽  
Diffraction Patterns ◽  
Operational Modes

The HB5 STEM instrument at ASU has been modified previously to include an efficient two-dimensional detector incorporating an optical analyser device and also a digital system for the recording of multiple images. The detector system was built to explore a wide range of possibilities including in-line electron holography, the observation and recording of diffraction patterns from very small specimen regions (having diameters as small as 3Å) and the formation of both bright field and dark field images by detection of various portions of the diffraction pattern. Experience in the use of this system has shown that sane of its capabilities are unique and valuable. For other purposes it appears that, while the principles of the operational modes may be verified, the practical applications are limited by the details of the initial design.

Single-peak-regulation and wide-angle dual-band metamaterial absorber based on hollow-cross and solid-cross resonators

2020 ◽  
Vol 91 (3) ◽  
pp. 30901
Author(s):  
Yibo Tang ◽  
Longhui He ◽  
Jianming Xu ◽  
Hailang He ◽  
Yuhan Li ◽  
...  
Keyword(s):  
Transverse Electric ◽  
Surface Current ◽  
Dielectric Substrate ◽  
Transverse Magnetic ◽  
Metamaterial Absorber ◽  
Absorption Peak ◽  
Dual Band ◽  
Single Peak ◽  
Wide Angle ◽  
Surface Current Density

A dual-band microwave metamaterial absorber with single-peak regulation and wide-angle absorption has been proposed and illustrated. The designed metamaterial absorber is consisted of hollow-cross resonators, solid-cross resonators, dielectric substrate and metallic background plane. Strong absorption peak coefficients of 99.92% and 99.55% are achieved at 8.42 and 11.31 GHz, respectively, which is basically consistent with the experimental results. Surface current density and changing material properties are employed to illustrate the absorptive mechanism. More importantly, the proposed dual-band metamaterial absorber has the adjustable property of single absorption peak and could operate well at wide incidence angles for both transverse electric (TE) and transverse magnetic (TM) waves. Research results could provide and enrich instructive guidances for realizing a single-peak-regulation and wide-angle dual-band metamaterial absorber.

Numerical study of the effect of transverse magnetic field on cylindrical and hemispherical CZ crystal growth of silicon

2010 ◽  
Vol 46 (4) ◽  
pp. 393-402 ◽  
Author(s):  
F. Mokhtari ◽  
A. Bouabdallah ◽  
A. Merah ◽  
S. Hanchi ◽  
A. Alemany
Keyword(s):  
Magnetic Field ◽  
Crystal Growth ◽  
Transverse Magnetic Field ◽  
Numerical Study ◽  
Transverse Magnetic

scholarly journals Strain Sensor via Wood Anomalies in 2D Dielectric Array

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1022
Author(s):  
Rashid G. Bikbaev ◽  
Ivan V. Timofeev ◽  
Vasiliy F. Shabanov
Keyword(s):  
Higher Plants ◽  
Numerical Study ◽  
Reciprocal Lattice ◽  
Strain Sensing ◽  
Photonic Materials ◽  
Sensing Applications ◽  
Wide Range ◽  
Sensor Structure ◽  
Optical Behavior ◽  
Chlorophyll Absorption

Optical sensing is one of many promising applications for all-dielectric photonic materials. Herein, we present an analytical and numerical study on the strain-responsive spectral properties of a bioinspired sensor. The sensor structure contains a two-dimensional periodic array of dielectric nanodisks to mimic the optical behavior of grana lamellae inside chloroplasts. To accumulate a noticeable response, we exploit the collective optical mode in grana ensemble. In higher plants, such a mode appears as Wood’s anomaly near the chlorophyll absorption line to control the photosynthesis rate. The resonance is shown persistent against moderate biological disorder and deformation. Under the stretching or compression of a symmetric structure, the mode splits into a couple of polarized modes. The frequency difference is accurately detected. It depends on the stretch coefficient almost linearly providing easy calibration of the strain-sensing device. The sensitivity of the considered structure remains at 5 nm/% in a wide range of strain. The influence of the stretching coefficient on the length of the reciprocal lattice vectors, as well as on the angle between them, is taken into account. This adaptive phenomenon is suggested for sensing applications in biomimetic optical nanomaterials.

scholarly journals Independently Tunable Multipurpose Absorber with Single Layer of Metal-Graphene Metamaterials

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 284
Author(s):  
Chen Han ◽  
Renbin Zhong ◽  
Zekun Liang ◽  
Long Yang ◽  
Zheng Fang ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Fermi Level ◽  
Potential Application ◽  
Single Layer ◽  
Wide Band ◽  
Metamaterial Absorber ◽  
Unit Cell ◽  
Perfect Absorption ◽  
Solar Energy Harvesting ◽  
Band Absorption

This paper reports an independently tunable graphene-based metamaterial absorber (GMA) designed by etching two cascaded resonators with dissimilar sizes in the unit cell. Two perfect absorption peaks were obtained at 6.94 and 10.68 μm with simple single-layer metal-graphene metamaterials; the peaks show absorption values higher than 99%. The mechanism of absorption was analyzed theoretically. The independent tunability of the metamaterial absorber (MA) was realized by varying the Fermi level of graphene under a set of resonators. Furthermore, multi-band and wide-band absorption were observed by the proposed structure upon increasing the number of resonators and resizing them in the unit cell. The obtained results demonstrate the multipurpose performance of this type of absorber and indicate its potential application in diverse applications, such as solar energy harvesting and thermal absorbing.

scholarly journals Ring-Forming Polymerization toward Perfluorocyclobutyl and Ortho-Diynylarene-Derived Materials: From Synthesis to Practical Applications

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1486
Author(s):  
Eugene B. Caldona ◽  
Ernesto I. Borrego ◽  
Ketki E. Shelar ◽  
Karl M. Mukeba ◽  
Dennis W. Smith
Keyword(s):  
Chemical Resistance ◽  
Structural Features ◽  
Review Article ◽  
Aryl Ether ◽  
Aromatic Rings ◽  
Practical Applications ◽  
Repeat Units ◽  
Wide Range ◽  
Synthetic Routes ◽  
The Cost

Many desirable characteristics of polymers arise from the method of polymerization and structural features of their repeat units, which typically are responsible for the polymer’s performance at the cost of processability. While linear alternatives are popular, polymers composed of cyclic repeat units across their backbones have generally been shown to exhibit higher optical transparency, lower water absorption, and higher glass transition temperatures. These specifically include polymers built with either substituted alicyclic structures or aromatic rings, or both. In this review article, we highlight two useful ring-forming polymer groups, perfluorocyclobutyl (PFCB) aryl ether polymers and ortho-diynylarene- (ODA) based thermosets, both demonstrating outstanding thermal stability, chemical resistance, mechanical integrity, and improved processability. Different synthetic routes (with emphasis on ring-forming polymerization) and properties for these polymers are discussed, followed by their relevant applications in a wide range of aspects.

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