scholarly journals Rough metal and dielectric layers make an even better hyperbolic metamaterial absorber

2014 ◽  
Vol 22 (12) ◽  
pp. 14975 ◽  
Author(s):  
Andrei Andryieuski ◽  
Sergei V. Zhukovsky ◽  
Andrei V. Lavrinenko
Keyword(s):  
Metamaterial Absorber ◽  
Hyperbolic Metamaterial ◽  
Dielectric Layers

scholarly journals Two-layered Dual-band Perfect Metamaterial Absorber at K band Frequency

2018 ◽  
Vol 7 (2) ◽  
pp. 25-27
Author(s):  
M. C. Tran ◽  
T. T. H. Phuong
Keyword(s):  
Metamaterial Absorber ◽  
Dual Band ◽  
Material Structure ◽  
Perfect Absorption ◽  
Band Frequency ◽  
Absorption Frequency ◽  
Dielectric Layers ◽  
Absorber Structure ◽  
Perfect Metamaterial Absorber ◽  
K Band

This paper presents a study of a novel absorber structure based on two-dielectric-layers, two perfect absorption frequency bands at K band (f1 = 26.5 GHz and f2 = 28.6 GHz) go under observance. The study of the dependence of absorption and frequency on relative distance between the layers of material and the material structure parameters are discussed. 

scholarly journals Effective Electrodynamics Theory for the Hyperbolic Metamaterial Consisting of Metal–Dielectric Layers

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 863
Author(s):  
Pi-Gang Luan
Keyword(s):  
Energy Density ◽  
Electromagnetic Fields ◽  
Lagrangian Density ◽  
Effective Medium ◽  
Polarization Field ◽  
Lagrangian Description ◽  
Dynamical Equations ◽  
Hamiltonian Density ◽  
Hyperbolic Metamaterial ◽  
Dielectric Layers

In this work, we study the dynamical behaviors of the electromagnetic fields and material responses in the hyperbolic metamaterial consisting of periodically arranged metallic and dielectric layers. The thickness of each unit cell is assumed to be much smaller than the wavelength of the electromagnetic waves, so the effective medium concept can be applied. When electromagnetic (EM) fields are present, the responses of the medium in the directions parallel to and perpendicular to the layers are similar to those of Drude and Lorentz media, respectively. We derive the time-dependent energy density of the EM fields and the power loss in the effective medium based on Poynting theorem and the dynamical equations of the polarization field. The time-averaged energy density for harmonic fields was obtained by averaging the energy density in one period, and it reduces to the standard result for the lossless dispersive medium when we turn off the loss. A numerical example is given to reveal the general characteristics of the direction-dependent energy storage capacity of the medium. We also show that the Lagrangian density of the system can be constructed. The Euler–Lagrange equations yield the correct dynamical equations of the electromagnetic fields and the polarization field in the medium. The canonical momentum conjugates to every dynamical field can be derived from the Lagrangian density via differentiation or variation with respect to that field. We apply Legendre transformation to this system and find that the resultant Hamiltonian density is identical to the energy density up to an irrelevant divergence term. This coincidence implies the correctness of the energy density formula we obtained before. We also give a brief discussion about the Hamiltonian dynamics description of the system. The Lagrangian description and Hamiltonian formulation presented in this paper can be further developed for studying the elementary excitations or quasiparticles in other hyperbolic metamaterials.

scholarly journals Investigation of surface roughness influence on hyperbolic metamaterial performance

2014 ◽  
Vol 3 (2) ◽  
pp. 6
Author(s):  
S. Kozik ◽  
M. A. Binhussain ◽  
A. Smirnov ◽  
N. Khilo ◽  
V. Agabekov
Keyword(s):  
Surface Roughness ◽  
Refractive Index ◽  
Composite Materials ◽  
Simple Model ◽  
Proper Selection ◽  
Hyperbolic Metamaterial ◽  
Computational Costs ◽  
Dielectric Layers ◽  
Dielectric Composite ◽  
Selection Of

The main goal of this work was to introduce simple model of surface roughness which does not involve objects with complicated shapes and could help to reduce computational costs. We described and proved numerically that the influence of surface roughness at the interfaces in metal-dielectric composite materials could be described by proper selection of refractive index of dielectric layers. Our calculations show that this model works for roughness with RMS value about 1 nm and below.

scholarly journals Triple-Band Anisotropic Perfect Absorbers Based on α-Phase MoO3 Metamaterials in Visible Frequencies

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2061
Author(s):  
Bin Tang ◽  
Neigang Yang ◽  
Xianglian Song ◽  
Gui Jin ◽  
Jiangbin Su
Keyword(s):  
Fdtd Method ◽  
Metamaterial Absorber ◽  
Geometrical Parameters ◽  
Absorption Bands ◽  
Perfect Absorption ◽  
Dielectric Layers ◽  
Α Phase ◽  
Photo Detectors ◽  
Resonant Grating ◽  
Triple Band

Anisotropic materials provide a new platform for building diverse polarization-dependent optical devices. Two-dimensional α-phase molybdenum trioxides (α-MoO3), as newly emerging natural van der Waals materials, have attracted significant attention due to their unique anisotropy. In this work, we theoretically propose an anisotropic perfect metamaterial absorber in visible frequencies, the unit cell of which consists of a multi-layered α-MoO3 nanoribbon/dielectric structure stacked on a silver substrate. Additionally, the number of perfect absorption bands is closely related to the α-MoO3 nanoribbon/dielectric layers. When the proposed absorber is composed of three α-MoO3 nanoribbon/dielectric layers, electromagnetic simulations show that triple-band perfect absorption can be achieved for polarization along [100], and [001] in the direction of, α-MoO3, respectively. Moreover, the calculation results obtained by the finite-difference time-domain (FDTD) method are consistent with the effective impedance of the designed absorber. The physical mechanism of multi-band perfect absorption can be attributed to resonant grating modes and the interference effect of Fabry–Pérot cavity modes. In addition, the absorption spectra of the proposed structure, as a function of wavelength and the related geometrical parameters, have been calculated and analyzed in detail. Our proposed absorber may have potential applications in spectral imaging, photo-detectors, sensors, etc.

Extending the absorption band from infrared to ultraviolet using the ITO transition from reflection to transparence

2021 ◽  
Author(s):  
Fathi Bendelala ◽  
Ali Cheknane ◽  
Mohammed Benatallah ◽  
Jean-Michel Nunzi
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
High Performance ◽  
Oblique Incidence ◽  
Metamaterial Absorber ◽  
The Finite Element Method ◽  
Absorption Bandwidth ◽  
Dielectric Layers ◽  
Simulation Based ◽  
Polarization Insensitive

A numerical simulation based on the finite-element method shows that a metamaterial absorber using Tungsten (W) and Indium tin oxide (ITO) plasmonic metals can be ultra-broadband and high-performance. Conventional broadband absorbers usually consist of multiple metal-dielectric layers or multi-resonators and have a bulky shape. The present investigates the possibility to reach optimal characteristics with a simple design by combining two plasmonic materials (W/ITO) within a single resonator. Involving the ITO transition from reflection to transparence dramatically increases the absorption bandwidth, which is extended from infrared to ultraviolet, with up to 99.92% absorption. The design is polarization-insensitive under oblique incidence, up to 75° and 80°, for TE and TM polarization waves, respectively.

Design and experimental verification of a perfect dual-band optical metamaterial absorber

2017 ◽  
Vol 31 (08) ◽  
pp. 1750047 ◽  
Author(s):  
Fenghua Ye ◽  
Huan Ye ◽  
Xiaozhi Wang
Keyword(s):  
Refractive Index ◽  
Gold Film ◽  
Internal Surface ◽  
Metamaterial Absorber ◽  
Dual Band ◽  
Surface Plasma ◽  
Local Surface ◽  
Environmental Media ◽  
Dielectric Layers ◽  
High Absorption

A perfect dual-band optical absorber is designed and measured. A low absorption peak (P1) and two high absorption peaks (P2 and P3) are obtained. The P1 peak is excited by the resonance of internal surface plasmon (ISP) mode. The P2 peak is resulted by the coupling of local surface plasma (LSP) modes and the resonance of ISP mode. The P3 peak is excited by the resonance of ISP mode. The damping constant of the gold film is optimization calculated in simulations. Measured results indicate that high absorption performed is obtained with different dielectric layers. The measured metamaterial absorber displays high absorption performed at TM and TE configurations. Moreover, the proposed metamaterial absorber is sensitivity on the change of the refractive index of the environmental media.

scholarly journals Ultra-Wideband and Wide-Angle Microwave Metamaterial Absorber

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2045 ◽  
Author(s):  
Xavier Begaud ◽  
Anne Lepage ◽  
Stefan Varault ◽  
Michel Soiron ◽  
André Barka
Keyword(s):  
Reflection Coefficient ◽  
Impedance Matching ◽  
Normal Incidence ◽  
Multilayered Structure ◽  
Metamaterial Absorber ◽  
Ultra Wideband ◽  
Wide Angle ◽  
Total Thickness ◽  
Dielectric Layers ◽  
Absorbing Materials

In order to extend the performance of radar absorbing materials, it is necessary to design new structures with wideband properties and large angles of incidence which are also as thin as possible. The objective of this work, realized within the framework of the SAFAS project (self-complementary surface with low signature) is, then, the development of an ultra-wideband microwave absorber of low thickness. The design of such material requires a multilayered structure composed with dielectric layers, metasurfaces, and wide-angle impedance matching layers. This solution has been realized with on-the-shelf materials, and measured to validate the concept. At normal incidence, the bandwidth ratio, defined for a magnitude of the reflection coefficient below −10 dB, is 4.7:1 for an absorber with a total thickness of 11.5 mm, which corresponds to λ/7 at the lowest operating frequency. For an incidence of 60°, this bandwidth ratio is reduced to 3.8:1, but the device remains ultra-wideband.

scholarly journals Multiple Sharp Fano Resonances in a Deep-Subwavelength Spherical Hyperbolic Metamaterial Cavity

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2301
Author(s):  
Ping Gu ◽  
Yuheng Guo ◽  
Jing Chen ◽  
Zuxing Zhang ◽  
Zhendong Yan ◽  
...  
Keyword(s):  
Electric Fields ◽  
Near Field ◽  
Energy Difference ◽  
Fano Resonances ◽  
Hyperbolic Metamaterial ◽  
Whispering Gallery ◽  
Field Coupling ◽  
Dielectric Layers ◽  
Potential Applications ◽  
Plasmon Modes

We theoretically study the multiple sharp Fano resonances produced by the near-field coupling between the multipolar narrow plasmonic whispering-gallery modes (WGMs) and the broad-sphere plasmon modes supported by a deep-subwavelength spherical hyperbolic metamaterial (HMM) cavity, which is constructed by five alternating silver/dielectric layers wrapping a dielectric nanosphere core. We find that the linewidths of WGMs-induced Fano resonances are as narrow as 7.4–21.7 nm due to the highly localized feature of the electric fields. The near-field coupling strength determined by the resonant energy difference between WGMs and corresponding sphere plasmon modes can lead to the formation of the symmetric-, asymmetric-, and typical Fano lineshapes in the far-field extinction efficiency spectrum. The deep-subwavelength feature of the proposed HMM cavity is verified by the large ratio (~5.5) of the longest resonant wavelength of WGM1,1 (1202.1 nm) to the cavity size (diameter: 220 nm). In addition, the resonant wavelengths of multiple Fano resonances can be easily tuned by adjusting the structural/material parameters (the dielectric core radius, the thickness and refractive index of the dielectric layers) of the HMM cavity. The narrow linewidth, multiple, and tunability of the observed Fano resonances, together with the deep-subwavelength feature of the proposed HMM cavity may create potential applications in nanosensors and nanolasers.

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