Right-handed Media Research Articles

Analysis of wave propagation through inhomogeneous left and right-handed media using the SPPS method

Solutions of the wave equation are analyzed considering the propagation of electromagnetic fields through a non-homogeneous stratified metamaterial medium. These solutions are obtained by two methods: (1) Spectral Parameter Power Series (SPPS) and (2) SPPS with Operator Transmutation (OT). This last method is considered an innovation for this application. Numerical solutions are obtained for left-handed (LH) and right-handed (RH) media, which allow their reflectance and transmittance coefficients to be calculated. The performance of each method is evaluated by comparing their solutions with the exact ones available and with those obtained by the differential transfer matrix method (DTMM). The advantages and limitations of each method are indicated.

Propagation of adjustable anomalous hollow Gaussian beams in the cascade of left-handed and right-handed media

In this paper, the propagation characteristics of adjustable anomalous hollow Gaussian beams are investigated in different cascaded systems composed of left-handed medium and right-handed medium. The propagation expressions of adjustable anomalous hollow Gaussian beams through different cascaded systems are derived, and the effects of negative refractive index and beam parameters on the propagation characteristics are analyzed in detail. It is found that when the negative refractive index changes, the position of the maximum axial intensity is different for different cascades. But the magnitude of the maximum axial intensity is not affected by the negative refractive index. The effects of negative refractive index and beam parameters on the beam width and intensity pattern evolution are also analyzed in detail. Although the propagation characteristics in this paper are obtained under certain parameters, it is very convenient to study the evolution characteristics under various conditions through the analytical formula obtained in this paper.

Interaction of plane waves with the edge discontinuity of a half-sheet at the interface of two different media

The present work considers the interaction of plane waves with a conductive half-sheet at the boundary of left- and right-handed media. The shadow boundary shifts toward the lower surface of the half-plane because of the anomalous refraction property of left-handed medium. For this reason, the diffracted fields are modified slightly by dividing into its subfields in order to satisfy the boundary conditions. The uniform version of fields is obtained and the results are plotted and discussed for different sets of parameters.

Diffraction by a right angle impedance wedge between left- and right-handed media

ABSTRACTAn analytical solution for the diffraction of plane waves by a right angle impedance wedge which is lying between double negative and positive materials is investigated. In order to satisfy the boundary conditions and shifted shadow boundary, the diffracted fields are divided to subfields. As a result, an anomalous shift of shadow boundary is observed towards to lower surface of the wedge. In addition, geometric optics fields are determined by using the geometry of the problem. Also, the behavior of the fields is investigated numerically.

艾里高斯涡旋光束正负交变介质中的光波演变

艾里高斯涡旋光束正负交变介质中的光波演变

Stable diffraction-management soliton in a periodic structure with alternating left-handed and right-handed media

In this paper, we first derive a modified two-dimensional non-linear Schrödinger equation including high-order diffraction (HOD) suitable for the propagation of optical beam near the low-diffraction regime in Kerr non-linear media with spatial dispersion. Then, we apply our derived physical model to a designed two-dimensional configuration filled with alternate layers of a left-handed material (LHM) and a right-handed media by employing the mean-field theory. It is found that the periodic structure including LHM may experience diminished, cancelled, and even reversed diffraction behaviours through engineering the relative thickness between both media. In particular, the variational method analytically predicts that close to the zero-diffraction regime, such periodic structure can support stable diffraction-management solitons whose beamwidth and peak amplitude evolve periodically with the help of HOD effect. Numerical simulation based on the split-step Fourier method confirms the analytical results.

The effective periodic homogeneous metamaterials for infinite complementary dielectric slab characteristics

A comparison of balanced and unbalanced backward wave dispersion relations and the constitutive electromagnetic effective parameters of dielectric constant, magnetic permeability are obtained. In the balanced case, the initial transmission line lies in left handed (LH) medium and the next to cut-off frequency of higher order regions transmission line becomes in right-handed (RH) medium. In the unbalanced case, there are a tiny reject band displays due to the attenuations. It is also desirable for metamaterial parameters extraction properties should behave in antiresonance behaviour in the band gap regions. The proposed extraction technique shows the suitable results for dual negative magnetic permeability and electric permittivity that match with the theory. To demonstrate the infinite wave investigations, there are four unit cell of complementary split- ring resonators (CSRRs) microstrip implementation is obtained and the equivalent lumped element circuit is analyzed. The theory and experiment result exhibits excellent agreement that ensures minimum loss and electrical small size due to less than wavelength dimensions.

Numerical study of two-dimensional metamaterial composites: the existence of a stop band

Two-dimensional metamaterial photonic crystals composed of dispersive left-handed materials and a right-handed medium were investigated. The existence of a stop band was studied by finite-difference time-domain calculations incorporated into an auxiliary differential equation (FDTD-ADE) method. The existence of a stop band was studied in the case of Drude-type dispersion responses for the dielectric permittivity and magnetic permeability of the metamaterial. A distinct stop band appears when the dispersive left-handed metamaterials are embedded in a positive-refractive-index medium and spatially isolated from each other. In contrast, the stop band is absent when the metamaterials span the entire photonic crystal.

SURFACE PLASMONS IN COAXIAL METAMATERIAL CABLES

Thanks to Victor Veselago for his hypothesis of negative index of refraction, meta-materials — engineered composites — can be designed to have properties difficult or impossible to find in nature: they can have both electrical permittivity (ϵ) and magnetic permeability (μ) simultaneously negative. The metamaterials — henceforth negative-index materials (NIMs) — owe their properties to subwavelength structure rather than to their chemical composition. The tailored electromagnetic response of the NIMs has had a dramatic impact on classical optics: they are becoming known to have changed many basic notions related with electromagnetism. The present article is focused on gathering and reviewing fundamental characteristics of plasmon propagation in coaxial cables fabricated of the right-handed medium (RHM) (with ϵ > 0, μ > 0) and the left-handed medium (LHM) (with ϵ < 0, μ < 0) in alternate shells starting from the innermost cable. Such structures as conceived here may pave the way to some interesting effects in relation to, for example, optical science exploiting the cylindrical symmetry of coaxial waveguides that make it possible to perform all major functions of an optical fiber communication system in which the light is born, manipulated, and transmitted without ever leaving the fiber environment, with precise control over the polarization rotation and pulse broadening. This review also covers briefly the nomenclature, classification, potential applications, and the limitations (related, for example, to the inherent losses) of the NIMs and their impact on classical electrodynamics in general, and in designing the cloaking devices in particular. A recent surge in efforts on invisibility and the cloaking devices seems to have spoiled the researchers worldwide: proposals include not only a way to hide an object without having to wrap the cloak around it, but also to replace a given object with another, thus adding to the deception even further! All this is attributed as much to the fundamental as to the practical advances made in the fabrication and characterization of NIMs. The article concludes briefly addressing the anticipated implications of plasmon observation in the multicoaxial cables and suggesting future dimensions worth adding to the problem. The background provided is believed to make less formidable the task of future writers of reviews in this field.

Surface waves on the interface between a left-handed and a right-handed medium

The frequency regions where a surface wave (SW) exists on a dielectric/metamaterial interface are determined for the case when the metamaterial’s refractive index is negative. With allowance for the conditions of TE and TM SW existence in the structure, the characteristic frequencies that can be controlled with the help of the external magnetic field are calculated. On the basis of dispersion dependences for SWs, it is shown that the TM (TE) wave is forward (backward), and the backward wave is substantially slowed in the structure.

Theory of confined plasmonic waves in coaxial cylindrical cables fabricated of metamaterials

We report on the theoretical investigation of the plasmonic wave propagation in the coaxial cylindrical cables fabricated of both right-handed medium (RHM) [with $\epsilon >0$, $\mu >0$] and left-handed medium (LHM) [with $\epsilon(\omega) <0$, $\mu(\omega) <0$], using a Green-function (or response function) theory in the absence of an applied magnetic field. The Green-function theory generalized to be applicable to such quasi-one dimensional systems enables us to derive explicit expressions for the corresponding response functions (associated with the EM fields), which can in turn be used to derive various physical properties of the system. The confined plasmonic wave excitations in such multi-interface structures are characterized by the electromagnetic fields that are localized at and decay exponentially away from the interfaces. A rigorous analytical diagnosis of the general results in diverse situations leads us to reproduce exactly the previously well-known results in other geometries, obtained within the different theoretical frameworks. As an application, we present several illustrative examples on the dispersion characteristics of the confined (and extended) plasmonic waves in single- and double-interface structures made up of dispersive metamaterials interlaced with conventional dielectrics. These dispersive modes are also substantiated through the computation of local as well as total density of states. It is observed that the dispersive components enable the system to support the simultaneous existence of s- and p-polarization modes in the system. Such effects as this one are solely attributed to the negative-index metamaterials and are otherwise impossible...

Localized modes in defective multilayer structures

In this paper, the localized surface modes in a defective multilayer structure has been investigated. It is shown that the defective multilayer structures can support two different kind of localized modes depending on the position and the thickness of the defect layer. One of these modes is localized at the interface between the multilayer structure and a homogeneous medium (the so-called surface mode) and the other one is localized at the defect layer (defect localized mode). We reveal that the presence of defect layer pushes the dispersion curve of surface modes to the lower or the upper edge of the photonic bandgap depending on the homogeneous medium is a left-handed or right-handed medium (e.g. vacuum), respectively. So, the existence region of the surface modes restricted. Moreover, the effect of defect on the energy flow velocity of the surface modes is discussed.

Simulations and realizations of active right-handed metamaterials with negative refractive index

The theory of determining the sign of the refractive index in active materials is discussed. Animations of numerical simulations are presented, supporting the claim that negative refractive index may occur in right-handed media. An example of such a medium, in the form of a lumped circuit model with active and passive resonances, is presented.

Enhanced localization of Dyakonov-like surface waves in left-handed materials

We theoretically investigate the existence and properties of hybrid surface waves forming at interfaces between left-handed materials and dielectric birefringent media. The existence conditions of such waves are found to be highly relaxed in comparison to the original hybrid surface waves, discovered by Dyakonov, in configurations involving birefringent materials and right-handed media. Hybrid surface waves in left-handed materials feature remarkable properties: (i) a high degree of localization and (ii) coexistence of several guided solutions. The existence of several hybrid surface waves for the same parameter set is linked to the birefringent nature of the medium whereas the strong localization is related to the presence of the left-handed material. The hybrid surface modes appear for large areas in the parameter space.

Anomalous Positive Refraction in an Anisotropic Left-Handed Medium

We investigate the refraction phenomena of extraordinary light at aplanar interface associated with a uniaxial left-handed medium. It isfound that the anomalous positive refraction can occur at the interfacefrom an isotropic right-handed medium to a uniaxially anisotropicleft-handed medium. When the optical axis of a uniaxial left-handedmedium is not normal or parallel to the interface, the refraction of thePoynting vector for the extraordinary waves can be either positive ornegative depending on the incident angles, while the refraction of thewave vector is always negative. The physical essential of the anomalouspositive refraction results from the anisotropy of uniaxial crystals.

Left-handed and right-handed metamaterials composed of split ring resonators and strip wires

The behavior of two structures composed of split ring resonators (SRRs) and strip wires (SWs) is examined through full wave simulations. It is shown that both structures exhibit a transmission peak in the region where the real parts of the electric permittivity and magnetic permeability are presumed to be negative, a property which is usually assumed to imply a negative index of refraction. However, an analysis of the dispersion characteristics and insertion phase of the two structures shows that the first structure, in which the SRRs and SWs are printed on opposite sides of a dielectric substrate, is a left-handed medium in the passband, whereas the second structure, in which SRRs and SWs are printed on the same side, is a right-handed medium in the passband. Hence the transmission magnitude alone does not provide sufficient evidence of a negative index of refraction. To determine the sign of the index correctly, the insertion phase for propagation through several lengths of the structure or calculations of dispersion diagrams are necessary. The impact of the unit cell size on the "handedness" of the structure is also examined.

Fedorov Lateral Shift at the Interface between Left-Handed and Right-Handed Media

The Fedorov lateral shift of a polarized beam upon the total internal reflection of light from an interface between media with positive and negative refractive indices is investigated. It is shown that the Fedorov lateral shift depends substantially on the polarization of the incident beam. The prediction is made that the Fedorov lateral shift can be completely compensated upon the total internal reflection of linearly polarized modes from two boundaries of a planar waveguide with a substrate prepared from a left-handed material.

Goos-Hänchen shifts at the interfaces between left- and right-handed media.

The Goos-Hänchen shift caused by total internal reflection at the interface between two media is analyzed. For two media of the same handedness the Goos-Hänchen phase shift opposes the phase variation associated with propagation through the incident medium. The Goos-Hänchen lateral shift is in the same direction as the horizontal component of the incident energy flux. Conversely, for two media of opposite handedness the Goos-Hänchen phase shift reinforces the phase variation associated with propagation through the incident medium. The lateral shift is in the opposite direction of the horizontal component of the incident energy flux.

Nonlinear surface waves in left-handed materials.

We study both linear and nonlinear surface waves localized at the interface separating a left-handed (LH) medium (i.e., a medium with both negative dielectric permittivity and negative magnetic permeability) and a conventional [or right-handed (RH)] dielectric medium. We demonstrate that the interface can support both TE- and TM-polarized surface waves-surface polaritons, and we study their properties. We describe the intensity-dependent properties of nonlinear surface waves in three different cases, i.e., when both the LH and RH media are nonlinear and when either of the media is nonlinear. In the case when both media are nonlinear, we find two types of nonlinear surface waves, one with the maximum amplitude at the interface, and the other one with two humps. In the case when one medium is nonlinear, only one type of surface wave exists, which has the maximum electric field at the interface, unlike waves in right-handed materials where the surface-wave maximum is usually shifted into a self-focusing nonlinear medium. We discuss the possibility of tuning the wave group velocity in both the linear and nonlinear cases, and show that group-velocity dispersion, which leads to pulse broadening, can be balanced by the nonlinearity of the media, so resulting in soliton propagation.

Power propagation in homogeneous isotropic frequency-dispersive left-handed media.

We study transmission at a boundary between a right-handed medium (RHM: epsilon>0, mu>0) and a frequency dispersive left-handed medium [LHM: epsilon(omega)<0, mu(omega)<0 for some omega], both homogeneous and isotropic. In order to account for the dispersion, two types of signal spectra are considered. The first consists of two discrete frequencies, while the second is Gaussian. Explicit expressions for the time-domain fields are obtained, from which the time-averaged Poynting vectors and hence power flow vectors are calculated. In both cases, we find that waves refract at negative angles at a RHM-LHM interface.