Discrete diffraction on a cascade-induced periodic lattice

A method for cascade generation of a periodic lattice in a medium with quadratic nonlinearity is proposed. Such a lattice is induced as a result of interference of two or four crossed fundamental-frequency waves. Numerical simulation of the discrete diffraction of a signal beam coupled to one of the lattice waveguides is performed. With an increase in the modulation depth of the refractive index, the signal wave is trapped in the waveguide.     

Discrete diffraction and waveguiding of optical beams in a cascade-induced lattice

Regularities of anisotropic discrete diffraction in a cascade-induced lattice formed by two crossed pump waves in a quadratically nonlinear medium have been studied. The transition from diffraction of a signal beam in free space to discrete diffraction with further capture into a waveguide in a defocusing lattice with an increase in the pump wave intensity has been traced. Diffraction-free propagation of a tilted beam is described.     

Impact of a DC magnetic field on evanescent wave intensity amplification for a magnetocompensated antiferromagnet

The impact of a dc magnetic field on evanescent TE and TM waves at the interface of transparent media comprising a semiconductor layer and a semi-infinite antiferromagnet is investigated using Otto geometry as an example. It is shown that switching a dc magnetic field orthogonal to a sagittal plane allows maximum amplification of the intensity of propagating evanescent TM or TE waves in both a layer and in semi-infinite space. The optimum conditions correspond to the formation of a peculiar TM or TE surface wave.     

Finite Alternation Theorems and a Constructive Approach to Piecewise Polynomial Approximation in Chebyshev Norm

Set-Valued and Variational Analysis - One of the purposes in this paper is to provide a better understanding of the alternance property which occurs in Chebyshev polynomial approximation and...     

Asymmetric hydrogenation ofN-acetyldehydrodipeptide complexes with Mg(II) and Ca(II) ions

N-Ac--Phe-AA form labile complexes with Mg(II) ions. Potentiometric titration data show that the carboxyl group of the dehydrodipeptide in them scarcely participates in complexation, unlike the complexes with Ca(II) ions. The hydrogenation of these complexes over Pd/C occurs asymmetrically, the diastereomeric excess being as high as 58%.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 601–602, March, 1993.     

Bivariate rational approximations of the general temperature integral

Journal of Mathematical Chemistry - The non-isothermal analysis of materials with the application of the Arrhenius equation involves temperature integration. If the frequency factor in the...     

Discrete diffraction in a cascade-induced anisotropic lattice

The features of anisotropic discrete diffraction in a cascade-induced lattice formed by two crossed pump waves in a quadratically nonlinear medium have been studied. The transition from the diffraction of a signal beam in free space to discrete diffraction with the further capture in a waveguide in a defocusing lattice by the increasing of the pump wave intensity has been traced.     

Lost branches in the spectrum of Parekh waves

It has been shown that a traditional approach to the calculation of a Parekh wave (a shear surface acoustic wave propagating along the mechanically free surface of a ferromagnet laterally magnetized by a static external magnetic field) including magnetoelastic interaction and neglecting magnetostriction inadequately describes the spectrum of the wave in the high-frequency range.     

Interface between an optically isotropic medium and a one-dimensional magnetoelectric photonic crystal as a controlled frequency-selective surface

The effect a constant external magnetic field has on the magnitude and direction of an energy flux carried by evanescent TM or TE wave in a two-component one-dimensional magnetic photonic crystal of the centroantisymmetric antiferromagnetic type (a nonmagnetic insulator) is investigated.