scholarly journals Dual polarized engineering the extinction cross-section of a dielectric wire using graphene-based oligomers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shiva Hayati Raad ◽  
Zahra Atlasbaf
Keyword(s):  
Cross Section ◽  
Transverse Electric ◽  
Transverse Magnetic ◽  
Infinite Length ◽  
Dielectric Cylinder ◽  
Fano Resonances ◽  
Spherical Nanoparticles ◽  
Extinction Cross Section ◽  
One Dimensional ◽  
Incident Plane

AbstractIn this paper, graphene-coated spherical nanoparticles are arranged around an infinite length dielectric cylinder to enhance its extinction cross-section. Initially, a single longitudinal one-dimensional periodic array is considered in different loci concerning the transverse electric (TE) incident plane wave. It is observed that regardless of the position of the particles, the extinction cross-section of the dielectric cylinder is considerably enhanced with respect to the bare one. Later, by increasing the number of longitudinal plasmonic arrays around the cylinder, each residing in a different azimuthal direction, the extinction cross-section is further manipulated to observe double pronounced Fano resonances. The origin of the Fano resonances is described by considering their planar counterparts constructed by the periodic assembly of plasmonic oligomers. Finally, the hexamer configuration is considered as the prototype, and the effect of various optical, geometrical, and material parameters on the optical response is investigated in detail. Interestingly, due to the spherical symmetry of the cells, the extinction cross-section is also enhanced for the transverse magnetic (TM) incident wave, which is unattainable using a continuous plasmonic cover made of metal or graphene. The potential application of our proposed structure is in the design of reconfigurable conformal optical absorbers and sensors.

Electromagnetic scattering from a coated notched cylinder

1989 ◽  
Vol 67 (6) ◽  
pp. 587-591
Author(s):  
R. Ruppin ◽  
H. Yatom
Keyword(s):  
Cross Section ◽  
Electromagnetic Scattering ◽  
Transverse Electric ◽  
Transverse Magnetic ◽  
Physical Parameters ◽  
Incident Plane Wave ◽  
Backscattering Cross Section ◽  
Incident Plane ◽  
Scattering Spectra ◽  
Electromagnetic Resonances

The problem of electromagnetic scattering of a normally incident plane wave from a coated conducting notched cylinder is solved. The coating material and the notch material are arbitrary dielectrics, and the incident wave is either transverse electric or transverse magnetic polarized. The numerical results of backscattering cross-section calculations are presented, and the dependence of the cross section on the various physical parameters is investigated. The coated notched cylinder system possesses characteristic electromagnetic resonances that manifest themselves in the scattering spectra.

On the inversion and phase recovery of scattered electromagnetic amplitude data

1989 ◽  
Vol 426 (1871) ◽  
pp. 361-375 ◽  
Keyword(s):  
Electromagnetic Scattering ◽  
Transverse Electric ◽  
Complex Structure ◽  
Polarization State ◽  
Scattering Problem ◽  
Transverse Magnetic ◽  
One Dimensional ◽  
Amplitude Data ◽  
Transverse Magnetic Polarization ◽  
The One

The one-dimensional inverse electromagnetic scattering problem for the inversion of amplitude data of either linear polarization state is investigated. The method exploits the complex structure of the field scattered from a class of inhomogeneous dielectrics and enables the analytic signal to be reconstructed from measurements of the amplitude alone. The method is demonstrated and exemplified with experimental data in both transverse electric and transverse magnetic polarization states. The implications of the method as a means for regularization of scattered data are briefly discussed.

Realization of tunable TE/TM wave splitter with one-dimensional plasma dielectric photonic crystal

2018 ◽  
Vol 32 (23) ◽  
pp. 1850253 ◽  
Author(s):  
K. F. Shen ◽  
B. Guo
Keyword(s):  
Magnetic Field ◽  
Photonic Crystal ◽  
Transverse Electric ◽  
Incident Angle ◽  
Transverse Magnetic ◽  
Dielectric Medium ◽  
Frequency Region ◽  
The Other ◽  
Reflection And Transmission ◽  
One Dimensional

A tunable transverse electric (TE) and transverse magnetic (TM) wave splitter using one-dimensional plasma dielectric photonic crystal which consists of plasma arranged periodically in a host dielectric medium is proposed. We performed a detailed study to explore the phenomena of reflection and transmission that occurs on obliquely incident electromagnetic wave propagating in the proposed plasma dielectric photonic crystal. We exactly calculated the transmittance based on the transfer matrix method. We find that if the parameters are selected appropriately, in the TE-stop or TM-stop frequency region, the other polarized component TM or TE wave is totally transmitted. The results also show that the dielectric constant, plasma thickness, incident angle and the applied magnetic field have significantly changed the properties of the TE/TM wave splitter. Moreover, the external magnetic field can be used as a kind of tunable method once the splitter is fabricated. Parameter dependence of the effects for the TE/TM wave splitter is calculated and discussed.

Design Considerations Influencing Optical Response in Gold Spherical Nanoparticles

2017 ◽  
Vol 46 ◽  
pp. 1-11 ◽  
Author(s):  
Amir Maghoul ◽  
Ali Rostami ◽  
Samiyeh Matloub ◽  
Amin Pourrezaei
Keyword(s):  
Cross Section ◽  
Silicon Nanoparticles ◽  
Optical Response ◽  
Resonant Peak ◽  
Core Shell ◽  
Spherical Nanoparticles ◽  
Shell Nanoparticles ◽  
Extinction Cross Section ◽  
The Core ◽  
Core Shell Nanoparticles

In this article, the relations between extinction cross section and Gold nanoparticle's parameters such as dimensions have been investigated. In this work, the extinction cross section of the core-shell nanoparticles is analyzed by changing the shell material and its thickness. By this, the interesting results such as shifting resonant peak in optical response are obtained. Moreover, a new model of nanostructure is proposed in which the resonant peak of extinction cross section can be controlled by adding silicon nanoparticles and impurity in the shell. This method can be used for tuning of the scattering properties of the core-shell nanoparticle. In the following, we demonstrate that the effective epsilon properties can be used for tuning of the desired optical response in the combinational structure of the spherical nanoparticles. At the end, the effective relative epsilon is also calculated for the selected structures. The operational frequency band is selected from 300 (THz) to 900 (THz).

Optimum power generation from a moving plasma

1960 ◽  
Vol 7 (2) ◽  
pp. 287-301 ◽  
Author(s):  
Joseph L. Neuringer
Keyword(s):  
Magnetic Field ◽  
Cross Section ◽  
Transverse Magnetic Field ◽  
Fusion Reaction ◽  
Transverse Magnetic ◽  
External Loading ◽  
One Dimensional ◽  
Dimensional Flow ◽  
Special Cases ◽  
Moving Plasma

The possibility exists of directly using the plasma, resulting from a controlled fusion reaction, to generate electricity by electromagnetic induction. Two special cases of a more general problem are considered here: (1)the extraction of optimum power from the steady one-dimensional flow of an incompressible inviscid plasma across a uniform transverse magnetic field in an externally loaded channel of arbitrarily varying cross-section, and (2) the extraction of optimum power from the steady one-dimensional flow of a compressible inviscid plasma across a uniform transverse magnetic field in a channel of uniform cross-section. In each case, the magnitude of the required external loading at optimum power operation is determined as a function of the parameters which characterize the hydromagnetic interaction. Also determined are the magnitudes of the terminal voltate, power, fluid mechanical to electrical conversion efficiency, and the variation of the fluid dynamical variables along the channel at optimum power.

scholarly journals Elusive Pure Anapole Excitation in Homogenous Spherical Nanoparticles with Radial Anisotropy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Wei Liu ◽  
Bing Lei ◽  
Jianhua Shi ◽  
Haojun Hu ◽  
Andrey E. Miroshnichenko
Keyword(s):  
Cross Section ◽  
Plane Waves ◽  
Far Field ◽  
Spherical Nanoparticles ◽  
Magnetic Dipoles ◽  
Anisotropic Dielectric ◽  
Scattered Power ◽  
Incident Plane ◽  
Total Scattering Cross Section ◽  
Radial Anisotropy

For homogenous isotropic dielectric nanospheres with incident plane waves, Cartesian electric and toroidal dipoles can be tunned to cancel each other in terms of far-field scattering, leading to the effective anopole excitation. At the same time however, other multipoles such as magnetic dipoles with comparable scattered power are simultanesouly excited, mixing with the anopole and leading to a nonnegligible total scattering cross-section. Here, we show that, for homogenous dielectric nanospheres, radial anisotropy can be employed to significantly suppress the other multipole excitation, which at the same time does not compromise the property of complete scattering cancallation between Cartesian electric and toroidal dipoles. This enables an elusivepure anopoleexcitation within radially anisotropic dielectric nanospheres, which may shed new light on many scattering related fundamental researches and applications.

scholarly journals Nonrigorous symmetric second-order ABC applied to large-domain finite element modeling of electromagnetic scatterers

2016 ◽  
Vol 29 (4) ◽  
pp. 675-688 ◽  
Author(s):  
Slobodan Savic ◽  
Milan Ilic
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Transverse Electric ◽  
Transverse Magnetic ◽  
Second Order ◽  
Electromagnetic Analysis ◽  
Absorbing Boundary ◽  
Large Domain ◽  
First Order ◽  
New Variables

Nonrigorous symmetric second-order absorbing boundary condition (ABC) is presented as a feasible local mesh truncation in the higher-order large-domain finite element method (FEM) for electromagnetic analysis of scatterers in the frequency domain. The ABC is implemented on large generalized curvilinear hexahedral finite elements without imposing normal field continuity and without introducing new variables. As the extension of our previous work, the method is comprehensively evaluated by analyzing several benchmark targets, i.e., a metallic sphere, a dielectric cube, and NASA almond. Numerical examples show that radar cross section (RCS) of analyzed scatterers can be accurately predicted when the divergence term is included in computations nonrigorously. An influence of specific terms in the second-order ABC, which absorb transverse electric (TE) and transverse magnetic (TM) spherical modes, is also investigated. Examples show significant improvements in accuracy of the nonrigorous second-order ABC over the first-order ABC.

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.

scholarly journals Aggregation affects optical properties and photothermal heating of gold nanospheres

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yiru Wang ◽  
Zhe Gao ◽  
Zonghu Han ◽  
Yilin Liu ◽  
Huan Yang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Cross Section ◽  
Laser Heating ◽  
Dipole Approximation ◽  
Gold Nanospheres ◽  
Extinction Cross Section ◽  
Heating Efficiency ◽  
Photothermal Heating ◽  
New Framework ◽  
Laser Calorimetry

AbstractLaser heating of gold nanospheres (GNS) is increasingly prevalent in biomedical applications due to tunable optical properties that determine heating efficiency. Although many geometric parameters (i.e. size, morphology) can affect optical properties of individual GNS and their heating, no specific studies of how GNS aggregation affects heating have been carried out. We posit here that aggregation, which can occur within some biological systems, will significantly impact the optical and therefore heating properties of GNS. To address this, we employed discrete dipole approximation (DDA) simulations, Ultraviolet–Visible spectroscopy (UV–Vis) and laser calorimetry on GNS primary particles with diameters (5, 16, 30 nm) and their aggregates that contain 2 to 30 GNS particles. DDA shows that aggregation can reduce the extinction cross-section on a per particle basis by 17–28%. Experimental measurement by UV–Vis and laser calorimetry on aggregates also show up to a 25% reduction in extinction coefficient and significantly lower heating (~ 10%) compared to dispersed GNS. In addition, comparison of select aggregates shows even larger extinction cross section drops in sparse vs. dense aggregates. This work shows that GNS aggregation can change optical properties and reduce heating and provides a new framework for exploring this effect during laser heating of nanomaterial solutions.

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