The propagation of electromagnetic waves through a disordered layered system is considered in the paradigm of the homogenization of Maxwell’s equations. Although the accuracy of the effective dielectric permittivity and/or magnetic permeability is still unclear outside the static approximation, we show that the effective wave vector can be correctly introduced even in high-frequency cases. It is demonstrated that both the real and imaginary parts of the effective wave vector are self-averaging quantities connected by the Kramers–Kronig relations. We provide a unified approach to describe the propagation and localization of electromagnetic waves in terms of the effective wave vector. We show that the effective wave vector plays the same role in describing composite materials in electrodynamics as the effective dielectric permittivity does in statics.
Integrated ring laser gyroscopes are perfect candidates for small-sized and high-performance gyroscopes. However, the performance of the ring laser gyroscope (RLG) near zero angular velocity is fundamentally restricted by the mode locking effect. In the paper the magneto-optical ring resonator is studied as a sensitive element of the integrated RLG. The counter-propagating waves are generated at the same frequency for resonator at rest and are spatially split. It is shown that the spatial splitting of modes in such a resonator drastically suppresses the mode locking problem even at the near zero angular velocity.
We study the nonlinear positive map of the density matrix of two-qubit Werner states, called the nonlinear channel. The map → Φ() is realized by the rational function Φ. We discuss the influence of the map on the entanglement properties of the transformed density matrix. We investigate the violation of the Bell inequality (CHSH inequality) for the two-qubit state Φ(). The nonlinear channels under discussion create the entangled state from a separable Werner state. We study the quantum spin tomograms of the states.
The creation of composite coatings with assigned optical properties is an important problem of modern science and technology. We have considered the metal-polymer nanocomposites based on poly(p-xylylene), with various concentrations of plasmon components—silver nanoparticles. We have carried out the optical measurements of the reflection, transmission, scattering and absorption coefficients for the manufactured films. We have retrieved the effective optical parameters of the composite coatings. The theoretical estimations based on the scattering and absorption data show that the scattering effectively occurs on the clusters of metal nanoparticles. This significantly influences the optical properties of the composite coating.
The propagation of electromagnetic waves through disordered layered system is considered in the paradigm of Maxwell's equations homogenization. In spite of the impossibility to describe the system in terms of effective dielectric permittivity and/or magnetic permeability the unified way to describe the propagation and Anderson localization of electromagnetic waves is proposed in terms of the introduced effective wave vector (effective refractive index). It is demonstrated that both real and imaginary parts of the effective wave vector (contrary to effective dielectric permittivity and/or magnetic permeability) are the self-averaging quantities at any frequency. The introduced effective wave vector is analytical function of frequency; corresponding Kramers-Kronig relation generalizes the Jones-Herbert-Thouless formula.
The optical properties of inhomogeneous cerium dioxide (CeO2) films on aluminum (Al) sublayer are investigated. The dependencies of the reflection, scattering, and absorption of coherent electromagnetic radiation as functions of the incidence angle and polarization are studied. The experimental and numerical studies show the existence of an incidence angle at which the scattering and absorption of coherent radiation with s-polarization increase simultaneously and the specular reflection becomes just about a few percents. The angle corresponds to an excitation of Fabry-Perot resonator modes. This effect opens up great prospects for manipulation (tuning) of the reflection from the inhomogeneous films.