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The free-space dyadic Green function in electromagnetics is orthogonal to its own curl on any spherical surface whose center is the source point. [ABSTRACT FROM AUTHOR]

Presents a study which examined the interaction of electromagnetic waves with isotropic chiral media. Discussion on the Maxwellian electromagnetism; Origin of optically active media; Equations describing noncentrosymetric, isotropic micropolar solids; Details on the sourceless volume in which a planewave is propagating in the + z direction.

Effective-medium theories for electromagnetic constitutive parameters of particulate composite materials are theories of averages. Standard deviations are absent because of the lack of rigorous theories. But ensemble averages and standard deviations can be calculated from a rigorous theory of reflection by planar multilayers. Average reflectivities at all angles of incidence and two orthogonal polarization states for a multilayer composed of two kinds of electrically thin layers agree well with reflectivities for a single layer with the same overall thickness and a volume-weighted average of the relative permittivities of these two components. But the relative standard deviation can be appreciable depending on the angle of incidence and the polarization state of the incident illumination, and increases with increasing difference between the constitutive parameters of the two layers. This suggests that average constitutive parameters obtained from effective-medium theories do not have uniform validity for all calculations in which they might be used. [ABSTRACT FROM PUBLISHER]

Theoretical and experimental work was carried out on a terahertz metamaterial bandstop filter comprising an array of identical subwavelength resonators, each formed by fusing a pair of printable metallic U-shapes that have their openings pointing in opposite directions. Linear frequency tunability of the stopband electromagnetic response can be achieved by altering the overlap distance between the two fused shapes. Tuning does not significantly affect the strength or quality factor of the resonance. An approach to create mechanically tunable, dynamic terahertz filters is thereby suggested, with several functional advantages. Meanwhile, an effective equivalent circuit model based on self-inductance, mutual inductance, and capacitance has been proposed. [ABSTRACT FROM AUTHOR]

When the electrically thin unit cell of a laminated composite material is made of two bianisotropic sheets whose constitutive properties in the thickness direction are decoupled from the constitutive properties in the interfacial planes, the laminated composite material can be homogenized into a material, not all of whose constitutive parameters are independent of each other. This nonindependence of the constitutive dyadics of the constituent materials and the homogenized composite material is captured by two simple constraints, which may not hold if even one of the two constituent materials has more complicated constitutive properties than stated above. [ABSTRACT FROM AUTHOR]

As the variation of temperature alters the intrinsic carrier density in a semiconductor, numerical simulations indicate that the consequent variation of the relative permittivity in the terahertz regime provides a way to realize thermally tunable split-ring resonators. Electromagnetic metasurfaces and metamaterials that are thermally tunable in the terahertz regime can thus be implemented. [ABSTRACT FROM AUTHOR]

Abstract: When a (frequency-domain) boundary-value problem involving a homogeneous linear material is solved to assess the validity of the Post constraint, a conflict arises between the fundamental differential equations of electromagnetism in the chosen material and a naïve application of the usual boundary conditions. It is shown here that the conflict vanishes when the boundary conditions are properly derived from the fundamental equations, and the validity of the Post constraint in modern macroscopic electromagnetism is thereby reaffirmed. [Copyright &y& Elsevier]

The concept of the electromagnetic trinity comprising vacuum, anti-vacuum, and nihility is extended to a zone in the 4-D ℇr-μr phase space that was largely inaccessible until the recent emergence of negative-phase-velocity materials. Expressions for Fresnel coefficients are derived for the reflection of plane waves at the planar interface of vacuum and a homogeneous, isotropic, dielectric-magnetic medium with constitutive properties lying in that zone. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 265–270, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21323 [ABSTRACT FROM AUTHOR]

Planewave propagation with hyperbolic/hyperboliclike characteristics in uniaxial dielectric media is investigated. The phase velocity is positive with respect to the time-averaged Poynting vector for both evanescent and nonevanescent propagation in nondissipative media. A conceptualization of a uniaxial medium, which exhibits hyperboliclike planewave characteristics as a homogenized composite medium, is presented. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 363–367, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21350 [ABSTRACT FROM AUTHOR]

Electromagnetic band gap (EBG) structures of two different configurations implemented inside R120 rectangular waveguides (frequency range 10–15 GHz) are examined. The first configuration has a periodic, piecewise uniform variation of permittivity in the propagation direction. Two types of such one-dimensional (1D) EBG structures are analyzed, one with the unit cell comprising two dielectric layers, the other with three dielectric layers per unit cell. The second configuration is two-dimensional, with the unit cell along the propagation direction containing two sections, each of which is made of alternating pillars of two dielectric materials. The Bloch theorem is invoked for the ideal EBG structures, which are infinitely long in the propagation direction. The mode-matching method (MMM) is used for real 1D-EBG structures, which contain a finite number of unit cells, whereas a combination of the coupled-mode method (CMM) and the MMM is used for real 2D-EBG structures. Spectrums of the transmission coefficient of the fundamental mode for the 1D-EBG structures are computed and shown to compare favorably against experimental data. The effect of inserting a defect in 1D-EBG structures is demonstrated theoretically as well as experimentally. The band gaps computed for real and ideal 2D-EBG structures are compared as well. [ABSTRACT FROM AUTHOR]

Abstract: We investigated the Onsager relations in the context of electromagnetic constitutive relations of linear, homogeneous materials. We determined that application of the Onsager relations to the constitutive equations relating P and M to both E and B is in accord with Lorentz reciprocity as well as the Post constraint. Our conclusions are particularly significant for research on linear magnetoelectric materials. [Copyright &y& Elsevier]

A theory of reflection and transmission of normally incident plane waves to a chiral sculptured thin film (CSTF) is presented. It is based on a coupled wave approach, in which the handedness-reversing reflections at the medium's interfaces are combined with the handedness-preserving distributed reflection inside the CSTF. Explicit formulas for the various reflection and transmission coefficients are derived. The method is shown to provide acceptable quantitative agreement with the exact full electromagnetic analysis. [ABSTRACT FROM AUTHOR]

Two results about the planewave response of an isotropic, dielectric-magnetic, homogeneous, planar slab are deduced when the real parts of both the permittivity and the permeability are altered from positive to negative. First, the reflection and the transmission coefficients suffer phase reversals without change in their respective magnitudes. Second, the Goos-Hänchen shifts experienced by beams on total reflection reverse their directions. [ABSTRACT FROM AUTHOR]

The problem of the coupling of a surface dielectric grating to a structurally chiral volume grating is formulated and solved. The volume grating is a chiral sculptured thin film, which exhibits the circular Bragg phenomenon in distinct wavelength regimes. Two distinct interactions are involved: (i) those of linearly polarized and circularly polarized modes, and (ii) those of nonspecular modes with the specular Bragg phenomenons. Numerical studies show that the circular Bragg phenomenon is virtually immune to the presence of the surface grating. Hence, chiral STF filters can be diffraction-coupled to other optical elements. [ABSTRACT FROM AUTHOR]

Presents a study which compared tilt angles and ellipticities of transmitted and reflected plane waves and thin film helicoidal bianisotropic mediums (TFHBM). Engineering and control of transportation properties; Theoretical description of TFHBM; Numerical results.

Presents a study on the application of the Maxwell Garnet and Bruggeman formalisms to homogenize linear bianisotropic-in-bianisotropic particulate composite media with ellipsoidal inclusions. Numerical implementation and results; Iteration scheme presented; Conclusions.

The chiroferrite medium is conceptualized as a homogenized composite medium (HCM) comprising a magnetically biased ferrite and an isotropic chiral medium as its components. Numerical results are presented which show unambiguously that the HCM is fully bianisotropic with all four constitutive dyadics endowed with a gyrotropic structure. The magnetoelectric response properties depend critically on the chirality parameter and the volume fraction of its isotropic chiral component. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 18: 342–345, 1998. [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]

Abstract: The positive conclusion on the recognizable existence of the Tellegen parameter, which invalidates the Post constraint, arrived at in the Comment of Sihvola and Tretyakov through the solution of a boundary-value problem relies on a framework of macroscopic electromagnetism that lacks a microscopic basis. But the microscopic viewpoint underlying the framework of modern macroscopic electromagnetism invalidates the boundary conditions used therein, and instead validates the Post constraint. [Copyright &y& Elsevier]

Presents a response on the comments made regarding electromagnetic waves. Examination of propagation in natural materials; Claims related to the electromagnetic waves; List of responses regarding the issue.

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 concept of isorefractive chiral media is proposed, and the plane-wave response of the planar interface between two such media is derived. A comparison is made with the concept of isoimpedant chiral media. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 19: 350–352, 1998. [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]

Constitutive scalars that are absent in the fundamental differential equations of frequency-domain electromagnetism on the two sides of a boundary between two homogeneous mediums are shown to disappear from the boundary conditions as well. © Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 56–57, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21259 [ABSTRACT FROM AUTHOR]

Introduces articles on exotic electromagnetics. Subdiscipline of complex-mediums electromagnetics; Phenomenon of negative refraction due to homogeneous mediums; Elucidation of the difference between negatively refracting mediums and mediums with negative refractive index; Significance of morphology; Effects of morphological perturbations of chiral sculptured thin films.

A correction to the article "Dyadic Green Function for an Electromagnetic Medium Inspired by General Relativity" that was published in a previous issue of the periodical is presented.

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]

Liu et al. are incorrect in claiming that previously derived expressions of the Green dyadics for homogeneous, isotropic chiral media are not “good enough.” In fact, nothing new has been presented in the subject paper. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 26: 65, 2000. [ABSTRACT FROM AUTHOR]

Considers the homogenization of a composite medium formed by randomly dispersing electrically small, cubically nonlinear, dielectric spheres in a homogeneous, linear, gyrotropic, dielectric host medium. Use of the Maxwell Garnett formalism to estimate the effective response properties of the homogenized composite medium; Technological applications of such composite media.

Electromagnetic absorption in a photoresist layer sandwiched between a silicon substrate and a quartz binary phase-shifting mask (employed in near-field phase shift contact lithography) is theoretically analyzed. A rigorous coupled-wave analysis is used to compute the distribution of specific absorption rate (SAR) in the photoresist layer on either monochromatic and polychromatic illumination. The nonuniform distribution of the SAR in the photoresist layer for the printing of high-aspect-ratio features is systematically examined in relation to the geometric dimensions of the binary phase mask, the photoresist layer thickness, and the polarization state of the incident plane wave. Two methods for the improvement of feature resolution and profile are also discussed. [Copyright &y& Elsevier]