Wave diffraction on an infinite chaotic screen bounding a medium with spatial and time dispersion

Electromagnetic wave diffraction on a chaotic screen, bounding a medium with time and spatial dispersion, has been investigated. The longitudinal and cross-correlation functions of waves in the limit cases of the correlation radius being longer or shorter than the wavelength have been evaluated. This letter considers the radiation of a plane antenna with dimensions much larger than the wavelength and with arbitrary current distribution on the surface; the antenna radiates into dielectric half-space with spatial and time dispersion.     

A new class of surface magnetic TM polaritons in crystals with linear magnetoelectric effect

The conditions necessary for the formation of a new type of a surface magnetic TM polariton at the magnetic dielectric-nonmagnetic metal or the magnetic dielectric-nomagnetic dielectric interfaces are determined. The formation of a surface electromagnetic wave of this type is caused by the effect of spatial dispersion of a magnetic dielectric medium.     

Nonlinear dispersion relation for surface plasmon at a metal-Kerr medium interface

The dispersion relation for the plasmon at the interface of a metal and a nonlinear Kerr medium is studied by applying a semi-analytic theory established in the literature. Explicit analytical results are obtained and are compared to those from a certain approximate treatment appeared in the literature. It is found that for large electric field strengths, both the dispersion relation and the surface plasmon frequency from the approximate treatment deviate significantly from those obtained in the exact approach, especially for the case with a negative Kerr susceptibility.     

Study on spatial dispersion theory of excess conduction loss in normal metals surface below terahertz frequencies

We have developed a rigorous model for analyzing excess conduction loss in normal metals surface by using the spatial dispersion theory. We have used the model to account excess conduction loss and dissect the discrepancies between excess conduction loss measurements and classical theoretical predictions in normal metals surface below terahertz frequencies. Our analysis shows that the conductivity is not only frequency but also wave vector dependent. We demonstrate good quantitative agreement with the published experimental data for the room temperature excess conduction loss of normal metals surface below terahertz frequencies.     

On the quasioptical approximation in dissipative media with spatial dispersion

A new form of the quasioptical equation is proposed to describe the propagation of an electromagnetic wave beam in a stationary smoothly inhomogeneous medium with spatial dispersion and dissipation. The proposed approach guarantees the positive definiteness of the absorbed power in the locally dissipative medium, which is a nontrivial property for inhomogeneous media with spatial dispersion. An efficient numerical scheme is constructed to solve the derived quasioptical equation.     

Quasi elasto-electromagnetic surface waves on a piezo-plasma-like layer

Considering a piezo-plasma-like layer with finite thickness and hexagonal symmetry whose main symmetry axis is parallel to the z axis and approximating it by an isotropic medium, we study the coupling of the elastic wave with plasma properties of the medium with and without spatial dispersion and collisions. In this case we investigate the coupled surface quasi elasto-electromagnetic wave propagating on the interface of piezoelectric layer with vacuum. Furthermore, the coupling of elasticity and ion-acoustic waves is investigated.     

Quasi elasto-electromagnetic surface waves on a piezo-plasma-like layer

Considering a piezo-plasma-like layer with finite thickness and hexagonal symmetry whose main symmetry axis is parallel to the z axis and approximating it by an isotropic medium, we study the coupling of the elastic wave with plasma properties of the medium with and without spatial dispersion and collisions. In this case we investigate the coupled surface quasi elasto-electromagnetic wave propagating on the interface of piezoelectric layer with vacuum. Furthermore, the coupling of elasticity and ion-acoustic waves is investigated.     

Dispersion relation for surface-localized magnetic polaritons and magnetostatic waves in antiferromagnetic superlattice

In addition to the general dispersion equation for surface-localized magnetic polaritons and magnetostatic waves, which propagate in the system antiferromagnetic superlattice-antiferromagnet, we derive a simplified result for the long-wavelength limit λ?L (L is the period of superlattice) when the superlattice is found to behave like an anisotropic bulk medium (effective-medium approach). The dispersion curves and frequency region of the existence of the surface magnetic polaritons and magnetostatic waves are presented numerically for several values of the external magnetic field and for different antiferromagnetic materials.     

Transmission of light through a random small-angle scattering medium

A theory of random small-angle scattering is presented. The photon dispersion partial differential equation is derived and the dispersion coefficient characterizing the medium is introduced. The equation is solved for a spatial impulse. The modulation transfer function and the contrast loss are derived as a funcion of spatial frequency, dispersion coefficient, and object-to-image distance. The limitation on resolution is shown by an indeterminancy relation based on the dispersion coefficient. The dispersion angle (rms value of scattering angle) is calculated as an example.     

Charge interaction in layered systems with spatial dispersion

The potential electrostatic energy of a charge near the surface of a metal with a metal or a dielectric coating (adsorbate), on the interface between metal (semimetal) and insulator (electrolyte) and in layered thin-film sandwich-type systems (MIS structures) has been calculated. The influence of the metal and the dielectric epitaxial coatings of the metal surface upon the interaction of charges is investigated. Taking into account the spatial dispersion effects, it is shown that in thin films surrounded by a medium with a large dielectric constant, the Coulomb repulsion between electrons decreases.     

Boundary conditions in media with spatial dispersion

In this paper we discuss the structure of the kernel in the integral relationship between the electric field and the displacement field in a semi-infinite dielectric medium (for the exciton region of spectrum) in the presence of spatial dispersion. Using the model of coupled oscillators we derive an additional boundary condition as a function of frequency shift and damping of surface oscillators.     

The near field correlation spectrum of a metallic film

The spatial two-point coherence function of the thermal radiation field at subwave-distance from a metallic film is calculated within fluctuation electrodynamics. Long-range oscillations as a function of lateral separation are seen; we interpret their features by comparing to the dispersion relations of surface plasmon polariton modes on the thin film. The hybridization of the surface modes on the top and bottom interfaces leads to a beatnote in the field correlations, for specific detector setups.     

Surface magnetoplasmon-polariton in superlattices: effective medium approach

We report a magnetoplasmon-polariton spectra in superlattices made up of two alternating media A and B, where one of the layers shows spatial dispersion in its frequency dependent dielectric function. We have used a theoretical approach based on the effective medium theory to determine the expression for the dielectric tensor of the superlattice in the presence of a magnetic field. It is applied to find out the bulk and surface polariton dispersion relation, as well as the Attenuated Total Reflection (ATR) spectra. Numerical results are presented and discussed to illustrate our theoretical predictions, with emphasis on a particular choice of the exciton’s additional boundary conditions (ABC).     

Characteristics of Photonic Bandgap Fibres with Hollow Core＇s Inner Surface Coated by a Layer Material

Hollow core＇s inner surface coating in a photonic bandgap fibre （PBCF） is investigated by means of finite element method. The coat material and thickness-dependence dispersion curve and group velocity dispersion are numerically studied. The coating with materials of low index or small thickness will rise up the dispersion curve but will not induce surface modes. However, coating with materials of high index or big coat thickness will induce surface modes and avoided-crossings. By varying coat material＇s refractive index and thickness, the appearances of surface modes and avoided-crossings can be changed. It is found that the avoided-crossing can enormously enlarge the negative dispersion which can find applications in dispersion compensation. We numerically achieve a negative dispersion as large as -21416.15ps/nm/km. The results give a physical insight into the propagation properties of PBGFs with the hollow core coated by a layer of material and are of crucial significance in the applications of PBGF coating.     

Resonant excitation of evanescent spatial harmonics in medium formed by parallel metallic nanorods

The results of analytical modeling of the resonant excitation of evanescent harmonics in a medium formed by parallel metallic nanorods taking into account the spatial dispersion are presented. Analytical expressions are derived for the reflection and transmission coefficients, as well as for the amplitudes of electromagnetic waves inside the medium. These expressions are compared to similar expressions that were previously obtained using a local model of an ultimately anisotropic material without taking into account the spatial dispersion. The obtained expressions are simplified for various partial cases, including the superresolution imaging of a source that is located at a considerable distance from the metamaterial layer. A layer of a medium composed from finitesized wires is numerically simulated and it is demonstrated that, due to the effect of resonant excitation of evanescent spatial harmonics in the layer, subwavelength details of an object that is considerably distant from the layer can be distinguished inside of the layer.     

On dispersion relations for optical media with spatial dispersion

An estimate of the ratio of the contributions of relativistic and nonrelativistic factors to the Kramers-Kronig relations for a medium with spatial dispersion is performed in a form taking into account the relativistic requirement of the finiteness of the velocity of propagation of a signal. Even under conditions of comparatively strong spatial dispersion, in the case of Wannier-Mott excitons in typical semiconductors, this ratio proves to be very small—of the order of 10^?4, which justifies the conventional (nonrelativistic) form of the dispersion relations.     

Transformation of Hybrid Transverse Elastic Waves in Nonuniform Micropolar Media

Acoustical Physics - The features of propagation of coupled hybrid transverse elastic waves in a nonuniform dense micropolar medium with spatial dispersion are studied. It is shown that in the...     

Observation of solitary elastic surface pulses

The formation of solitary elastic surface pulses from laser-generated pulselike initial conditions is reported. The nonlinearity of the medium is compensated by both normal dispersion and anomalous dispersion, which were realized by coating isotropic fused silica by a metal and titanium nitride film, respectively. As an anisotropic material, silicon covered with an oxide layer was studied. The experimental results agree with numerical simulations carried out with a nonlocal evolution equation, which describes nonlinear propagation of surface acoustic waves in a dispersive medium.