Propagation of high-frequency electromagnetic waves through a magnetized plasma in curved space-time. II. Application of the asymptotic approximation

1981 ◽  
Vol 374 (1756) ◽  
pp. 65-86 ◽  
Keyword(s):  
High Frequency ◽  
Electromagnetic Waves ◽  
Polarization State ◽  
Space Time ◽  
Magnetized Plasma ◽  
Curved Space ◽  
Polarized Waves ◽  
Background Magnetic Field ◽  
Linearly Polarized ◽  
Unmagnetized Plasma

This is the second of two papers on the propagation of high-frequency electromagnetic waves through an inhomogeneous, non-stationary plasma in curved space-time. By applying the general two-scale W.K.B. method developed in part I to the basic wave equation, derived also in that paper, we here obtain the dispersion relation, the rays, the polarization states and the transport laws for the amplitudes of these waves. In an unmagnetized plasma the transport preserves the helicity and the eccentricity of the polarization state along each ray; the axes of the polarization ellipse rotate along a ray, relative to quasiparallely displaced directions, at a rate determined by the vorticity of the electron fluid; and the norm of the amplitude changes according to a conservation law which can be interpreted as the constancy of the number of quasiphotons. In a magnetized plasma the polarization state changes differently for ordinary and extraordinary waves, according to the angle between the wavenormal and the background magnetic field, and under specified approximation conditions the direction of polarization of linearly polarized waves undergoes a generalized Faraday rotation.

scholarly journals Propagation of high-frequency electromagnetic waves through a magnetized plasma in curved space-time. I

1980 ◽  
Vol 370 (1742) ◽  
pp. 389-406 ◽  
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Space Time ◽  
Magnetized Plasma ◽  
Asymptotic Solutions ◽  
Perturbation Equation ◽  
Partial Differential ◽  
Curved Space

This is the first of two papers on the propagation of high-frequency electromagnetic waves through a magnetized plasma in curved space-time. We first show that the nonlinear system of equations governing the plasma and the electromagnetic field in a given, external gravitational field has locally a unique solution for any initial data set obeying the appropriate constraints, and that this system is linearization stable at any of its solu­tions. Next we prove that the linearized perturbations of a ‘background’ solution are characterized by a third-order (not strictly) hyperbolic, constraint-free system of three partial differential equations for three unknown functions of the four space-time coordinates. We generalize the algorithm for obtaining oscillatory asymptotic solutions of linear systems of partial differential equations of arbitrary order, depending polynomially on a small parameter such that it applies to the previously established perturbation equation when the latter is rewritten in terms of dimensionless variables and a small scale ratio. For hyperbolic systems we then state a sufficient condition in order that asymptotic solutions of finite order, constructed as usual by means of a Hamiltonian system of ordinary differential equations for the characteristic strips and a system of transport equations determining the propagation of the amplitudes along the rays, indeed approximate solutions of the system. The pro­cedure is a special case of a two-scale method, suitable for describing the propagation of locally approximately plane, monochromatic waves through a dispersive, inhomogeneous medium. In the second part we shall apply the general method to the perturbation equation referred to above.

scholarly journals COLLISION OF HIGH FREQUENCY PLANE GRAVITATIONAL AND ELECTROMAGNETIC WAVES

2003 ◽  
Vol 12 (08) ◽  
pp. 1459-1473 ◽  
Author(s):  
P. A. HOGAN ◽  
D. M. WALSH
Keyword(s):  
Gravitational Waves ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Degrees Of Freedom ◽  
Geometrical Optics ◽  
Field Equations ◽  
Maxwell Theory ◽  
Polarized Waves ◽  
Linearly Polarized ◽  
Plane Gravitational Waves

We study the head-on collision of linearly polarized, high frequency plane gravitational waves and their electromagnetic counterparts in the Einstein–Maxwell theory. The post-collision space-times are obtained by solving the vacuum Einstein and Einstein–Maxwell field equations in the geometrical optics approximation. The head-on collisions of all possible pairs of these systems of waves is described and the results are then generalized to nonlinearly polarized waves which exhibit the maximum two degrees of freedom of polarization.

scholarly journals Design and experimental analysis of dual-band polarization converting metasurface for microwave applications

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Bilawal Khan ◽  
Babar Kamal ◽  
Sadiq Ullah ◽  
Imran Khan ◽  
Jawad Ali Shah ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Polarization State ◽  
Plane Waves ◽  
Microwave Frequency ◽  
Dual Band ◽  
Orthogonal Polarization ◽  
Frequency Bands ◽  
Practical Applications ◽  
Sensor Applications ◽  
Polarized Waves

Abstract The manipulation of polarization state of electromagnetic waves is of great importance in many practical applications. In this paper, the reflection characteristics of a thin and dual-band metasurface are examined in the microwave frequency regime. The metasurface consists of a 22 × 22 element array of periodic unit cells. The geometry of the unit cell consists of three layers, including a 45° inclined dipole shape metal patch on top, which is backed by a 1.6 mm thick FR-4 substrate in the middle, and a fully reflective metallic mirror at the bottom. The proposed surface is exposed to horizontally (x) or vertically (y) polarized plane waves and the co and cross polarization reflection coefficients of the reflected waves are investigated experimentally in the 6–26 GHz frequency range. The metasurface is designed to convert incident waves of known polarization state (horizontal or vertical) to orthogonal polarization state (vertical and horizontal) in two distinct frequency bands, i.e. 7.1–8 GHz and 13.3–25.8 GHz. In these two frequency bands the simulated and experimental results are in good agreement. The polarization conversion ratio (PCR) of the surface is greater than 95% in the targeted frequency bands. A detailed parametric analysis of the metasurface is also discussed in this work and it has been estimated that the surface has the additional ability to convert linearly polarized waves to circularly polarized waves at several distinct frequencies. The proposed metasurface can be utilized in sensor applications, stealth technology, electromagnetic measurements, and antennas design.

scholarly journals Dual-band dichroic asymmetric transmission of linearly polarized waves in terahertz chiral metamaterial

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3235-3242 ◽  
Author(s):  
Tingting Lv ◽  
Xieyu Chen ◽  
Guohua Dong ◽  
Meng Liu ◽  
Dongming Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Light Propagation ◽  
Polarization State ◽  
Dual Band ◽  
Terahertz Waves ◽  
Asymmetric Transmission ◽  
Polarized Waves ◽  
Wide Range ◽  
Linearly Polarized ◽  
Chiral Metamaterial

AbstractPolarization conversion dichroism is of particular interest in manipulating the polarization state of light, whereas high-performance asymmetric transmission (AT) of linearly polarized waves is still inaccessible in the terahertz range. Here, a bilayer chiral metamaterial consisting of orthogonally chained S-shaped patterns with broken symmetry along the light propagation direction is proposed and demonstrated experimentally to realize a dual-band dichroic AT effect for linearly polarized terahertz waves. The AT effects are robust across a wide range of incident angles. The observed strong AT can be theoretically explained by a multiple reflection and transmission interference model and the transfer matrix method. The proposed bilayer chiral metamaterial may have broad applications in polarization manipulation, chiral biosensing and direction-dependent information processing.

Scattering and Modulational Instabilities in Magnetized Plasmas

1974 ◽  
Vol 29 (12) ◽  
pp. 1736-1741 ◽  
Author(s):  
M. Y. Yu ◽  
K. H. Spatschek ◽  
P. K. Shukla
Keyword(s):  
High Frequency ◽  
Electromagnetic Waves ◽  
Wave Interaction ◽  
Scattered Wave ◽  
Magnetized Plasma ◽  
Stimulated Scattering ◽  
Frequency Wave ◽  
Electrostatic Wave ◽  
Linear Current ◽  
Modulational Instabilities

The decay of a high-frequency wave into a scattered and an electrostatic wave is investigated for a homogeneous magnetized plasma. For wave propagation in arbitrary directions, an equation for the scattered wave is obtained accounting for the effect of the non-linear current density produced by the three-wave interaction process. As an illustration, the propagation of electromagnetic waves perpendicular to the external magnetic field is considered. The growth rates and thresholds for the stimulated scattering and modulational instabilities are obtained. The influence of a weak inhomogeneity is also considered.

Double passage of electromagnetic waves through magnetized plasma: approximation of independent normal waves

Open Physics ◽  
2010 ◽  
Vol 8 (3) ◽  
Author(s):  
Yury Kravtsov ◽  
Bohdan Bieg
Keyword(s):  
Electromagnetic Wave ◽  
Characteristic Feature ◽  
Electromagnetic Waves ◽  
Polarization State ◽  
Normal Modes ◽  
Practical Interest ◽  
Magnetized Plasma ◽  
Fast Wave ◽  
Circularly Polarized ◽  
Normal Waves

AbstractPolarization properties of electromagnetic waves, double-passed through magnetized plasma, are studied. Analyses are performed in the case of non-interacting normal modes, propagating in homogeneous and weakly inhomogeneous plasmas, and for three kinds of reflectors: metallic plane, 2D corner retro-reflector (2D-CR), and cubic corner retro-reflector (CCR). It is shown that an electromagnetic wave, reflected from a metallic plane and from a CCR, contains only “velocity-preserving” channels, whose phases are doubled in comparison with those of a single-passage propagation. At the same time, an electromagnetic wave reflected from a 2D-CR is shown to contain both “velocity-preserving” and “velocity-converting” channels, the latter converting the fast wave into the slow one and vice-versa. One characteristic feature of “velocity-converting” channels is that they reproduce the initial polarization state near the source, which might be of practical interest for plasma interferometry. In the case of circularly polarized modes, “velocity-preserving” channels completely disappear, and only “velocity-converting” channels are to be found.

Stability of relativistic transverse cold plasma waves. Part 2. Linearly polarized waves

1979 ◽  
Vol 22 (2) ◽  
pp. 201-222 ◽  
Author(s):  
F. J. Romeiras
Keyword(s):  
Nonlinear Wave ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Transverse Modes ◽  
Electron Positron ◽  
Polarized Waves ◽  
Linearly Polarized ◽  
Linear Differential ◽  
Unmagnetized Plasma ◽  
The Stability

This is part 2 of a paper concerned with the stability against small perturbations of a certain class of nonlinear wave solutions of the equations that describe a cold unmagnetized plasma. It refers to transverse linearly polarized waves in an electron-positron plasma. A numerical method, based on Floquet's theory of linear differential equations with periodic coefficients, is used to solve the perturbation equations and obtain the instability growth rates. All the three possible types of perturbations are discussed for a typical value of the (large) amplitude of the nonlinear wave: electrically longitudinal slightly unstable modes (with maximum growth rate γ approximately equal to 0·07ω0, where ω0is the frequency of the nonlinear wave); purely transverse moderately unstable modes (with γ ≃ 0·26ω0); and highly unstable electrically transverse modes (with γ ≃ l·5ω0).

scholarly journals Dispersion relations for electromagnetic waves in a dense magnetized plasma

2008 ◽  
Vol 74 (6) ◽  
pp. 719-723 ◽  
Author(s):  
P. K. SHUKLA ◽  
L. STENFLO
Keyword(s):  
Electromagnetic Waves ◽  
Dispersion Relations ◽  
Magnetized Plasma ◽  
Intense Laser ◽  
Spin Effect ◽  
Bohm Potential ◽  
Electron Current Density ◽  
Astrophysical Objects ◽  
Linearly Polarized ◽  
Elliptically Polarized

AbstractDispersion relations for elliptically polarized extraordinary as well as linearly polarized ordinary electromagnetic waves propagating across an external magnetic field in a dense magnetoplasma are derived, taking into account the combined effects of the quantum electrodynamical (QED) field, as well as the quantum forces associated with the Bohm potential and the magnetization energy of the electrons due to the electron-1/2 spin effect. The QED (vacuum polarization) effects, which contribute to the nonlinear electron current density, modify the refractive index. Our results concern the propagation characteristics of perpendicularly propagating high-frequency electromagnetic waves in dense astrophysical objects (e.g. neutron stars and magnetars), as well as the next-generation intense laser–solid density plasma interaction experiments and quantum free-electron laser schemes.

scholarly journals Short-scale quantum kinetic theory including spin–orbit interactions

2021 ◽  
Vol 75 (1) ◽  
Author(s):  
R. Ekman ◽  
H. Al-Naseri ◽  
J. Zamanian ◽  
G. Brodin
Keyword(s):  
Kinetic Theory ◽  
Electromagnetic Waves ◽  
Orbit Interaction ◽  
Magnetized Plasma ◽  
Spin Orbit ◽  
Spin Orbit Interaction ◽  
Electrostatic Waves ◽  
Quantum Kinetic Theory ◽  
Unmagnetized Plasma ◽  
Spin Orbit Interactions

Abstract We present a quantum kinetic theory for spin-1/2 particles, including the spin–orbit interaction, retaining particle dispersive effects to all orders in $$\hbar $$ ħ , based on a gauge-invariant Wigner transformation. Compared to previous works, the spin–orbit interaction leads to a new term in the kinetic equation, containing both the electric and magnetic fields. Like other models with spin–orbit interactions, our model features “hidden momentum”. As an example application, we calculate the dispersion relation for linear electrostatic waves in a magnetized plasma, and electromagnetic waves in a unmagnetized plasma. In the former case, we compare the Landau damping due to spin–orbit interactions to that due to the free current. We also discuss our model in relation to previously published works. Graphic abstract

Dispersion of dipolar electromagnetic waves in a radially inhomogeneous axially magnetized plasma column

1997 ◽  
Vol 58 (4) ◽  
pp. 633-646 ◽  
Author(s):  
I. GHANASHEV ◽  
I. ARESTOVA ◽  
E. TATAROVA ◽  
I. ZHELYAZKOV ◽  
Sv. STOYKOV
Keyword(s):  
Plasma Density ◽  
Plasma Column ◽  
Electromagnetic Waves ◽  
Wave Attenuation ◽  
Magnetized Plasma ◽  
Plasma Inhomogeneity ◽  
Polarized Waves ◽  
Plasma Density Profile ◽  
Order Of Magnitude ◽  
Radially Inhomogeneous

The wavelengths and attenuation coefficients of dipolar left and right-hand circularly polarized waves in a radially inhomogeneous axially magnetized plasma column are computed by means of step approximation of the radial plasma density profile. A comparison with theoretical results assuming radial plasma homogeneity shows that the radial plasma inhomogeneity is significant for wave propagation. In particular, it facilitates the occurrence of backward waves and increases by up to one order of magnitude the wave attenuation coefficient compared with a homogeneous plasma column having the same average plasma density.

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