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The Bruggeman homogenization formalism was used to numerically investigate the dielectric properties of a columnar thin film (CTF) made from vanadium dioxide. For visible and near-infrared wavelengths, the CTF is electromagnetically equivalent to a homogeneous orthorhombic material. Over the 58–72 °C temperature range, the eigenvalues of the CTF's relative permittivity dyadic are highly sensitive to temperature and vary according to whether the CTF is being heated or cooled. The anisotropy revealed through the eigenvalues and the anisotropy of the associated hysteresis were investigated in relation to temperature for CTFs of different porosities and columnar cross sections. When the free-space wavelength is 800 nm, the CTF is a dissipative dielectric material that exhibits temperature-dependent anisotropy and anisotropic hysteresis. In contrast, when the free-space wavelength is 1550 nm, the CTF can be a dissipative dielectric material, a hyperbolic material, or a metal-like material, depending on the temperature and the porosity of the CTF. As the porosity of the CTF decreases from 0.55 to 0.3, the anisotropy of the CTF becomes more pronounced, as does the anisotropy of the hysteresis. Only relatively modest variations in anisotropy and hysteresis arise in response to varying the columnar cross-sectional shape, as compared to the variations induced by varying the porosity. [ABSTRACT FROM AUTHOR]

Electromagnetic surface waves guided by the planar interface of an isotropic dielectric medium and a uniaxial dielectric medium, both non-dissipative, were considered, the optic axis of the uniaxial medium lying in the interface plane. Whereas this interface is known to support the propagation of Dyakonov surface waves when certain constraints are satisfied by the constitutive parameters of the two partnering mediums, we identified a different set of constraints that allow the propagation of surface waves of a new type. The fields of the new surface waves, named Dyakonov-Voigt (DV) surface waves, decay as the product of a linear and an exponential function of the distance from the interface in the anisotropic medium, whereas the fields of the Dyakonov surface waves decay only exponentially in the anisotropic medium. In contrast to Dyakonov surface waves, the wavenumber of a DV surface wave can be found analytically. Also, unlike Dyakonov surface waves, DV surface waves propagate only in one direction in each quadrant of the interface plane. [ABSTRACT FROM AUTHOR]

Mathematical statements of the Huygens principle relate the electric and magnetic field phasors at an arbitrary location in a source-free region enclosed by a surface to the tangential components of the electric and magnetic field phasors over that surface, via the dyadic Green functions applicable to the linear homogeneous medium occupying that region. We have mathematically formulated the Huygens principle for the electric and magnetic field phasors when the permittivity and permeability dyadics of the medium are symmetric, the symmetric parts of the two magnetoelectric dyadics of the medium are negative of each other, and both magnetoelectric dyadics also contain anti-symmetric terms. We have also formulated the Huygens principle for the electric (resp. magnetic) field phasor in a medium whose permittivity (resp. permeability) is scalar, the permeability (resp. permittivity) is symmetric, the symmetric parts of the two magnetoelectric dyadics reduce to dissimilar scalars, and anti-symmetric parts of the two magnetoelectric dyadics are identical. [ABSTRACT FROM AUTHOR]

In passive structurally chiral materials (SCM's), because the manifestation of the defect-mode resonance as a transmission hole is prevented by the presence of even weak dissipation, experimental verification has been elusive. We have found that the insertion of a homogeneous anisotropic layer and careful matching of the geometric and the constitutive attributes of that layer in a three-layer structure containing two dissimilar SCM layers enable us to overcome the effect of weak dissipation-thereby enhancing the possibility of experimental verification with passive materials. [ABSTRACT FROM AUTHOR]

Abstract: The one-point boundary-value problem of reflection of an obliquely incident plane wave by a half space occupied by a linear helicoidal bianisotropic medium (HBM) was solved. The solution procedure relies on the HBM being at least slightly dissipative, and also yields a modal representation for the fields therein. The solution procedure should also apply for a half space containing any linear material that varies periodically in the normal direction. [ABSTRACT FROM AUTHOR]

Abstract: The spacetime metric of a spinning cosmic string may be formally represented in flat spacetime by a nonhomogeneous bianisotropic medium. The constitutive parameters of this bianisotropic medium can be established using a noncovariant formalism, thereby paving the way for laboratory simulations of a spinning cosmic string using metamaterial technology. [Copyright &y& Elsevier]

Abstract: The canonical perfect lens—comprising three slabs, each made of a linear, homogeneous, bianisotropic material with orthorhombic symmetry—is Lorentz covariant. [Copyright &y& Elsevier]

Abstract: We consider percolation thresholds which arise in the homogenization of composite mediums based on three different types of component particles. An extension of the standard Bruggeman homogenization formalism is implemented in order to take account of the sizes, shapes, and orientations of the component particles. The relationships between the geometric attributes of the component particles and the constitutive parameters of the homogenized composite mediums are investigated. In particular, percolation thresholds arising in the homogenization of conducting component particles oriented in two directions and nonconducting component particles are explored via representative numerical examples. Anisotropies in these percolation thresholds are highlighted. [Copyright &y& Elsevier]

Investigates the elastic constitutive properties of chiral sculptured thin films using the Mori-Tanaka average stress and the Eshelby tensor for ellipsoids. Details on the mean-field approach for anisotropic composite materials; Macroscopic constitutive relations of chiral sculptured thin films; Information on the localized homogenization of sculptured thin films.

The Bruggeman approach is implemented to homogenize a collection of identical, similarly oriented, electrically small, ellipsoidal particles with intensity-dependent refractive index that are dispersed randomly and homogeneously in an isotropic, linear, dielectric host material. The homogenized composite medium is assumed to be cubically nonlinear and anisotropic, in the simplest approximation. The anisotropy of nonlinearity may be considerably different from the anisotropy of the linearity. The possible enhancement of nonlinearity is also anisotropic, with the most desirable performance along the shortest principal axis of the ellipsoidal particles. [ABSTRACT FROM AUTHOR]

A material combining both mirror-conjugated and racemic chirality properties is characterized and classified within the context of linear bianisotropic mediums. Planewave propagation in the chosen material is studied with particular emphasis on the interaction of different and no handedness along certain specified directions. Comparison is made with isotropic chiral mediums as well as uniaxial bianisotropic mediums. [ABSTRACT FROM AUTHOR]

Chiroplasmas and chiroferrites were originally theoretically conceptualized as media which combine the properties of isotropic chiral media with those of dielectric/magnetic gyrotropic media. We clarify here a problem concerning the correct characterization of such media through their frequency-domain constitutive relations. Furthermore, we show that a homogenized composite medium with isotropic chiral and gyrotropic component media is considerably more complicated than envisioned: chiroplasmas and chiroferrites must be bianisotropic, combining gyrotropic dielectric/magnetic with gyrotropic-like magnetoelectric properties. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 17: 405–408, 1998. [ABSTRACT FROM AUTHOR]

The Maxwell curl postulates have been analyzed for propagation in vertical microstructurally significant plane of a periodically bent nemoic (PBN) medium. The ordinary modes are unaffected by the anisotropy and the periodic inhomogeneity of the PBN medium, but the extraordinary modes are. Simple expressions, applicable for small anisotropy parameters, have been found. [ABSTRACT FROM AUTHOR]

Summary: When a plane wave is launched from a plane surface in a linear, homogenous, dielectric–magnetic, uniaxial medium, we show that its phase velocity and the energy–transport velocity vectors can be counterposed (i.e., lie on different sides of the surface normal) under certain circumstances. [Copyright &y& Elsevier]

Relevant to the electromagnetic response of an electrically small, bianisotropic ellipsoid embedded in another bianisotropic medium, relationships are presented whereby the rotation/reflection of the constitutive dyadics and the orientation of the ellipsoid are linked together. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 175–177, 2000. [ABSTRACT FROM AUTHOR]

The frequency-dependent constitutive relations of a simple symmetric bianisotropic medium (SSBM) are stated as ${\b D}= {A}{\kern-0.8em \raise -1ex\hbox{=}} \cdot (\epsilon {\b E}- \beta {\b H}) \hbox{ and } {\b B}= {A}{\kern-0.8em \raise -1ex\hbox{=}} \cdot (\beta {\b E} + \mu {\b H})$, where A??? is a real symmetric dyadic. After an affine transformation is used, expressions for the fields in the source regions are derived for this medium. The obtained results may be used to determine the scattering response of an electrically small bianisotropic particle embedded in a SSBM, and can therefore also be used to homogenize a wide class of particulate composites. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 15: 84–86, 1997. [ABSTRACT FROM AUTHOR]

Scaling relations for time-dependent and time-harmonic electromagnetic fields and sources ate obtained, and the consequent scaling relations for the constitutive properties of linear bianisotropic materials are also derived. [ABSTRACT FROM AUTHOR]

Expressions for the plane-wave response of a unidirectionally conducting screen (UCS) embedded in a linear, homogeneous, bianisotropic substance are obtained. The ratio of the complex amplitudes of the two reflected plane waves is shown to be always independent of the ratio of the complex amplitudes of the two incident plane waves; likewise, for the transmitted plane waves. Thus, a UCS is a super-Brewster screen. [ABSTRACT FROM AUTHOR]

If all space is occupied by a linear bianisotropic material—whether homogeneous or not—then the concurrent replacements of the permittivity and the impermeability tensors by the negatives of their respective complex conjugates and of the magneto-electric tensors by their respective complex conjugates (in the Boys–Post representation) imply the conjugation of both E and H, in the absence of externally impressed sources. This conjugation symmetry in linear electromagnetism has observable consequences when the linear bianisotropic material occupies a bounded region. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 160–161, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11315 [ABSTRACT FROM AUTHOR]

Constitutive relations for a spatially, local and nonhomogeneous, temporally causal, linear bianisotropic medium without memory are given for use with the Beltrami-Maxwell postulates. [ABSTRACT FROM AUTHOR]

Three clarifications are provided with respect to certain statements of Dmitriev [Microwave Opt Technol Lett 29 (2001) 363–366]. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 402–402, 2001. [ABSTRACT FROM AUTHOR]

A surface electromagnetic wave called the Dyakonov-Tamm wave has been theoretically predicted to exist at the interface of two dielectric materials at least one of which is both anisotropic and periodically nonhomogeneous. For experimental confirmation, a prism-coupled configuration was used to excite Dyakonov-Tamm waves guided by the interface of a dense thin film of magnesium fluoride and a chiral sculptured thin film of zinc selenide. The excitation was indicated by a reflection dip (with respect to the angle of incidence in the prism-coupled configuration) that is independent of the polarization state of the incident light as well as the thicknesses of both partnering materials beyond some thresholds. Applications to optical sensing and long-range on-chip communication are expected. [ABSTRACT FROM AUTHOR]

Abstract: Columnar and chevronic thin films of GeSbSe chalcogenide glasses were grown by the oblique-angle-deposition technique. These thin films were found to exhibit dielectric anisotropy in the near-infrared regime. The retardance of any of the fabricated thin films was found to increase linearly with the thickness. Columnar thin films exhibited significantly lower retardance per unit thickness than chevronic thin films. The experimental results indicate the potential of these thin films for near-infrared polarizers. [Copyright &y& Elsevier]

Abstract: The differential method (also called the C method) is applied to the diffraction of linearly polarized plane waves at a periodically corrugated boundary between vacuum and a linear, homogeneous, uniaxial, dielectric–magnetic medium characterized by hyperbolic dispersion equations. Numerical results for sinusoidal gratings are presented and compared with those obtained by means of the Rayleigh method, showing that both the differential method and the Rayleigh method can fail to give adequate results for gratings supporting an infinite number of refracted Floquet harmonics. [Copyright &y& Elsevier]