Reflectance spectra may show very different and interesting shapes. The most interesting may be connected to Evans holes. Model calculations to reproduce this effect were done applying model dielectric function functions. When a weak oscillator appears within the frequency region of a strong one (i.e. between its TO and LO frequencies), its LO-mode frequency shifts towards higher wavenumbers. A...

The longitudinal and transverse components of the complex dielectric susceptibility tensor of an assembly of dipolar molecules rotating in an asymmetric double-well potential are evaluated using a fractional rotational diffusion equation (based on the diffusion limit of a fractal time random walk) for the distribution function of orientations of the molecules on the surface of the unit sphere. ...

We use a variational principle to derive a mathematical model for a nematic electrolyte in which the liquid crystalline component is described in terms of a second-rank order tensor. The model extends the previously developed director-based theory and accounts for presence of disclinations and possible biaxiality. We verify the model by considering a simple but illustrative example of liquid cr...

We obtain a short-distance expansion for the half-space, frequency domain electromagnetic Green’s tensor. The small parameter of the theory is ω 1L/c, where ω is the frequency, 1 is the permittivity of the upper half-space, in which both the source and the point of observation are located, and which is assumed to be transparent, c is the speed of light in vacuum and L is a characteristic length...

High Q-factor open-box mode resonances have been found in the microwave measurements of several 3-D printed dielectric-filled metal-pipe rectangular waveguides (MPRWGs). These parasitic Fabry-Perot eigenmodes are confined by conductive walls transverse plane MPRWG and partially air-dielectric dielectric-air boundaries longitudinal direction. The excitation modes was previously speculated to be ...

Polycrystalline textured thin films with distinct pleochroism and birefringence comprising oriented rotational domains of the orthorhombic polymorph an anilino squaraine isobutyl side chains (SQIB) are analyzed by imaging Mueller matrix ellipsometry to obtain biaxial dielectric tensor. Simultaneous fitting transmission oblique incidence reflection scans combined spatial resolution optical micro...

Abstract. We establish a general relation between dispersion forces. First, based on QED in causal media, leading-order perturbation theory is used to express both the single-atom CasimirPolder and the two-atom van der Waals potentials in terms of the atomic polarizabilities and the Green tensor for the body-assisted electromagnetic field. Endowed with this geometryindependent framework, we the...

1. Introduction It has been theoretically shown that backward waves can be supported not only by double-negative materials with simultaneous negative permittivity and permeability [1] but also by uniaxial anisotropic single-negative slabs with a negative component of permittivity or permeability tensor [2]. The uniaxial anisotropic single-negative materials are potentially advantageous in row l...

An automated computational strategy is devised for the ab initio determination of the full fourth-rank piezo-optic tensor of crystals belonging to any space group of symmetry. Elastic stiffness and compliance constants are obtained as numerical first derivatives of analytical energy gradients with respect to the strain and photo-elastic constants as numerical derivatives of analytical dielectri...