Dual-band asymmetric electromagnetic wave transmission for dual polarizations in chiral metamaterial structure

In this paper, we propose a chiral metamaterial structure that enables dual-band asymmetric transmission effect for different linearly polarized electromagnetic waves. The metamaterial is composed of metallic spirals with two split-ring resonators sandwiching a dielectric slab and connecting with via hole. Strong one-way transmission of two orthogonally polarized waves at different frequency bands has been confirmed through both full-wave simulation and test on fabricated prototype at the microwave band. Analysis also shows such asymmetric transmission can be attributed to the induced asymmetric current distributions in the spiral that support strong polarization conversion and cross-polarization transmission. By scaling down the metamaterial structure, the concept could also be utilized at other frequency bands, such as submillimeter or even terahertz band and find applications in designing one-way electromagnetic wave devices or polarization spectral filters.     

Scattering of electromagnetic waves from planar chiral structures

A rigorous solution is found for the problem of reflection of E- and H-polarized plane electromagnetic waves from a metal plane covered by a chiral layer of arbitrary thickness. The dependence of the electromagnetic wave reflection on the chirality parameter and the layer thickness is studied. The reflection of the depolarized component is examined. The results, obtained using two different forms of the constitutive relations for a chiral medium, are compared. State Volga Academy of Telecommunication and Information Science, Samara, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 9, pp. 870–878, September, 1999.     

Field generated by an anisotropic conducting plane in a half-space with chiral properties

This article inaugurates theoretical studies on a new class of composite structures that are a combination of anisotropically conducting surfaces and media possessing chiral properties. To test the mathematics, we solved the simplest model of the problem in which an in-phase electric current filament excites a plane formed by a layer of straight conductors at the interface of two isotropic media, one of which is chiral. The solution is given as a Fourier integral. As shown by analysis, one retarded wave of a discrete spectrum and three waves of a continuous spectrum are excited in the given structure. The first one exists only because of the anisotropically conducting plane and does not exist without it, while the latter three are associated with plane waves of corresponding homogeneous media, magnetodielectric and chiral.V. D. Kuznetsov Siberian Physicotechnical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 34–38, September, 1994.     

Plane Waves Propagating in Chiral Plasma and Chiral Ferrite Media

Plane wave propagation in chiral plasma and chiral ferrite media is studied in kDB coordinate system. General wave equations and characteristic equations of plane waves propagating along an arbitrary direction in chiral plasma and in chiral ferrites are derived in simple formulations respectively. Four wavenumbers and their corresponding dispersion characteristics are resulted for propagation both along and normal to the biasing magnetic field. When plane wave with negative helicity propagates along the biasing magnetic field in chiral ferrites, backward waves emerge. However backward waves occur with both positive and negative helicities when propagating along the biasing magnetic field in chiral plasma.     

Diode-like asymmetric transmission of circularly polarized waves

Optical diode plays an important role in optical computing and information processing. In this paper, a kind of three-layered chiral metamaterial is proposed to achieve diode-like asymmetric transmission for forward and backward propagations of circularly polarized electromagnetic waves only. The metamaterial is composed of a ring–chain structure sandwiched between two identical S-shaped metallic layers with their corresponding substrates. A transparent transmission at normal incidence in one direction and a small intensity of transmission in the opposite direction are numerically demonstrated in this chiral structure. Besides, the results reveal that the bandwidth of the cross-polarization transmission of this designed structure can be tuned by varying the incident angle of circularly polarized waves.     

Simulation of Characteristic Radiation of Highly Ionized Laser Plasma

In the tensor form, using the generalized Rayleigh–Gans–Debye approximation, the problem of the sum-frequency generation from a thin nonlinear layer deposited on a dielectric spherical particle placed in a dielectric medium is solved. The second-order nonlinear dielectric susceptibility tensor is chosen in a general form containing chiral components. In the vector and tensor forms, expressions are obtained that describe the spatial distribution of the sum-frequency radiation field generated by two plane electromagnetic elliptically polarized waves. Limiting expressions that describe the spatial distribution of the sum-frequency harmonic at small and large radii of the spherical layer are obtained. It is revealed that, at small radii of the spherical layer, the radiation due to the chiral anisotropy coefficients makes a dominant contribution to the generation.     

Reflection characteristics of chiral microwave absorbing coatings

The formulations of reflection coefficients for metal-backed one- and multi-layered chiral microwave absorbing coatings are derived in a much straight way in this paper. It is found that the propagation of normally incident plane waves in chiral coatings can be treated as in their achiral counterparts if the intrinsic impedance and wavenumber of the achiral structure are replaced by their associated chiral impedance and average chiral wavenumber, respectively. From a practical point of view, examples of one- and two-layered chiral microwave absorbing coatings are given, and the effects of the real and imaginary parts of the chiral admittance on the antireflection characteristics are examined for the first time, the results show that with a appropriate complex chiral admittance, the reduction in reflection can be enhanced and the minimum-reflection-frequency can be controlled.     

Xeros

It is demonstrated that scalar particles can have the same radiation zeros as those found in electromagnetism provided that their couplings have a form related to a local chiral transformation. This is satisfied in extended N = 2 supersymmetry and leads to checks on scalar gluon calculations and to solutions for matter fields interacting with scalar plane waves.     

Transformation of plane wave fields due to a parameter jump in a free magnetodielectric layer

The transformation of plane electromagnetic waves caused by a synchronous stepwise temporal change in the permittivity and permeability of a layer of a free anisotropic magnetodielectric medium is considered. No constraints are imposed on the layer thickness and the jump magnitude. The problem is solved analytically with the integral equation method. Exact expressions for the electric component of the field throughout the space after the jump are found. The expressions derived are analyzed from the physical viewpoint.     

On the effect of absorption on multiple wave-scattering in a magnetized turbulent plasma

Multiple scattering of electromagnetic waves by a plane layer of a turbulent magnetized collision plasma is considered. The influence of the distance between both the emitter and the receiver and the layer boundaries is analysed. It is found that the width of the angular spectrum of the received radiation for sufficiently strong absorption in the plasma is greater than in the collisionless plasma; the spectral maximum is substantially displaced with respect to the direction of the source. It is shown that these effects are weakened when the emitter approaches the layer. The relationship between the spectral width and also the displacement of its maximum and the distance from the receiver to the layer boundary may be substantially non-monotonic.     

On the theory of the radiation of an electron moving in the field of two plane waves and a magnetic field

The motion and radiation of electrons in a homogeneous magnetic field and the field of two plane waves propagating along the vector of the magnetic field intensity are considered. The law of motion and expressions for the total power, frequencies, and angular spectral distribution of the electron radiation intensity are obtained. An analysis is carried out of the results obtained in the case of small intensities of the plane waves. It is shown that the presence of the plane waves has a considerable effect on the characteristics of synchroton radiation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 105–110, August, 1977.     

The effect of electrical boundary conditions on the characteristics of surface acoustic waves propagating in potassium niobate

The study of the effect of a perfectly conducting plane placed at a certain distance from the surface of a potassium niobate crystal on the characteristics of the generalized Rayleigh and Gulyaev-Bleustein surface waves is continued. In addition, the effect of an infinitely thin conducting layer applied to the surface of the piezoelectric on the characteristics of these waves is analyzed. It is found that a variation in the conductance of this layer can produce a result that completely differs from the result obtained when a perfectly conducting plane is moved toward the surface, although the extreme states of these actions (electrically open and short-circuited surfaces) are identical. A possible physical explanation of this difference is proposed.     

Scattering response of a bianisotropic cylinder with electrically small cross-section

EM scattering response of an infinitely long bianisotropic cylinder with electrically small cross-section suspended in free space is presented. Formulation of this problem is based on the coupled integral equation method with the long wavelength approximation. Reduced expressions for the scattering of plane waves, both E-wave and H-wave types, are obtained. It is revealed that for certain polarization matrices determined by the constitutive parameters of the scatterer, cross-polarization and/or co-polarization phenomena may occur, respectively.     

Approximate method of solving the problem of diffraction of a plane electromagnetic wave by a thin chiral layer covering a perfectly conducting plane

One-sided approximate impedance-type boundary conditions for a thin chiral layer placed on a perfectly conducting plane are derived. With these conditions, the problem of incidence of a plane electromagnetic wave on a chiral structure is solved. Approximate formulas for the coefficients of reflection of the fundamental and depolarized components are derived for the case of the perpendicular polarization of the electromagnetic wave (the electric field strength is normal to the plane of incidence). A comparison with an exact solution to the problem of diffraction by this chiral structure is made.     

Studies on the spectral width,monochromatic degree and spectral resolving power of prism monochromator

The angular width and geometric line width in the spectral plane for the output incoherent imaging spectral line are discussed respectively on the basis of structure of prism monochromator, the relationship between the spectral width and line width of output incoherent imaging spectral line in the spectral plane is presented. The expression of monochromatic degree of output light in the exit slit plane is presented. The spectral resolving power of incoherent imaging spectral line and coherent imaging spectral line of the diffractive waves are discussed respectively, and the expressions of the spectral resolving power are presented respectively.     

On the effect of absorption on multiple wave-scattering in a magnetized turbulent plasma

Abstract

Multiple scattering of electromagnetic waves by a plane layer of a turbulent magnetized collision plasma is considered. The influence of the distance between both the emitter and the receiver and the layer boundaries is analysed. It is found that the width of the angular spectrum of the received radiation for sufficiently strong absorption in the plasma is greater than in the collisionless plasma; the spectral maximum is substantially displaced with respect to the direction of the source. It is shown that these effects are weakened when the emitter approaches the layer. The relationship between the spectral width and also the displacement of its maximum and the distance from the receiver to the layer boundary may be substantially non-monotonic.     

Determination of isotropic layer parameters from spatiotemporal signals of an ultrasonic array

The paper discusses a method for measuring the velocities and attenuation of longitudinal and transverse ultrasonic waves and the density and thickness of the isotropic layer with an array placed in an immersion liquid parallel to the sample. The method is based on the recording of the total spatiotemporal signal of the array and its expansion into a spatial spectrum of pulse plane wave response. The ultrasonic velocity and sample thickness depend on the response delay of the plane wave in the layer from the transverse projection of the slowness vector. The density and attenuation are determined from the behavior of the amplitudes of spectral responses. To confirm this method in experiment, the parameters of a polystyrene plate have been measured using a linear 32-element array with a central frequency of 17 MHz.     

Bulk and Surface Plane Waves Propagated in Chiroferrite in the Transverse Direction

The propagation of volume plane waves in a gyromagnetic chiral medium (chiroferrite) in the plane transverse to the magnetization direction and the propagation of surface waves in the half-space are investigated when an external magnetic field is applied perpendicularly to the direction of wave propagation along the boundary of the medium.     

电磁偏置各向异性石墨烯界面的传播矩阵

基于电磁场边界条件和相位匹配,推导出电、磁偏置下呈各向异性的石墨烯导电界面的传播矩阵,并进一步给出各向异性石墨烯界面的反透射系数解析解;该传播矩阵耦合了基本的横电波和横磁波极化,并包括偏置电、磁场的影响.将跨石墨烯界面传播矩阵嵌入各向同性分层介质传播矩阵,获得的新传播矩阵可用于解析分析平面电磁波以任意角度入射含各向异性...     

Chirality Driven by Magnetic Dipole Response for Demultiplexing of Surface Waves

Surface electromagnetic waves are characterized by the intrinsic spin‐orbit interaction which results in the fascinating spin‐momentum locking. Therefore, directional coupling of light to surface waves can be achieved through chiral nanoantennas. Here, we show that dielectric nanoantenna provides chiral response with strong spectral dependence due to the interference of electric and magnetic dipole momenta when placed in the vicinity of the metal‐air interface. Remarkably, chiral behaviour in the proposed scheme does not require elliptical polarization of the pump beam or the geometric chirality of the nanoantenna. We show that the proposed ultracompact and simple dielectric nanoantenna allows for both directional launching of surface plasmon polaritons on a thin gold film and their demultiplexing with a high spectral resolution.