scholarly journals Особенности локализации возбуждений вблизи прослойки между нелинейными фокусирующими средами с нелинейным взаимодействием с границами раздела слоев

2020 ◽  
Vol 62 (3) ◽  
pp. 457
Author(s):  
С.Е. Савотченко
Keyword(s):  
Nonlinear Response ◽  
Layer Structure ◽  
Finite Thickness ◽  
Localized States ◽  
Characteristic Scale ◽  
Nonlinear Crystals ◽  
Field Localization

The localized states in a three-layer structure consisting of two nonlinear crystals with positive nonlinearity, between which a linear plate of finite thickness is clamped, and the layer interfaces are characterized by a nonlinear response are arised. The frequencies of such localized states are obtained that exist only at different values of the intensity of interaction of the layer interfaces with excitations. The conditions for the existence of such states are found and estimates of the characteristic scale of field localization are obtained.

scholarly journals Локализация возбуждений в слоистой структуре с границами раздела, характеризующимися нелинейным откликом

2019 ◽  
Vol 61 (3) ◽  
pp. 571
Author(s):  
С.Е. Савотченко
Keyword(s):  
Surface Waves ◽  
Nonlinear Response ◽  
Layer Structure ◽  
Localized States ◽  
Frequency Range ◽  
One Dimensional ◽  
Localized State ◽  
Symmetric Structure ◽  
The Media ◽  
Field Localization

AbstractThe features of localization of excitations in a three-layer structure in which linear media are separated by boundaries with their own nonlinear response have been examined. It is shown that in the three-layer structure under consideration, localized states of two types can exist that differ in the distribution of the field in the inner layer, as well as in the frequency range of existence. Dispersion relations have been obtained that determine the energy dependence on system parameters in each case. The damping factors of surface waves are obtained in an explicit form. The conditions of the field localization are specified, depending on the characteristics of the layers and their interfaces. The energies of localized states have been found that do not exist in a symmetric structure without a wave interacting with the interfaces of the layers. Moreover, the presence of a nonlinear response of the boundaries is mandatory. It is shown that the interaction of a wave with the interfaces of the layers can lead to the absence of a localized state in a one-dimensional symmetric potential well with infinitely high walls and a nonlinear response. The influence of the media parameters and their interfaces on the flux carried by surface waves has been analyzed.

scholarly journals Моды волновода с пороговой нелинейностью

2020 ◽  
Vol 46 (16) ◽  
pp. 43
Author(s):  
С.Е. Савотченко
Keyword(s):  
Dielectric Constant ◽  
Optical Properties ◽  
Surface Waves ◽  
Nonlinear Optical ◽  
Layer Structure ◽  
Finite Thickness ◽  
Critical Value ◽  
Field Structure ◽  
Finite Width ◽  
Border Regions

A three-layer structure consisting of a nonlinear optical medium with a stepwise change in the dielectric constant inside which there is a dielectric layer of finite thickness is considered. The surface waves of two types of symmetry with a special field structure can propagate along the layers. Domains of finite width with different optical properties in the border regions in a nonlinear medium are formed. The formation of domains, as well as the existence of surface waves, occurs at interlayer thicknesses not exceeding a certain critical value.

scholarly journals Formation of artificially-Layered Thin-Film Compounds Using Pulsed-Laser Deposition

1995 ◽  
Vol 388 ◽  
Author(s):  
David P. Norton ◽  
B. C. Chakoumakos ◽  
D. H. Lowndes ◽  
J. D. Budai
Keyword(s):  
Thin Film ◽  
Pulsed Laser Deposition ◽  
Layer Structure ◽  
Finite Thickness ◽  
Pulsed Laser ◽  
Unit Cell ◽  
Laser Deposition ◽  
Thickness Variation ◽  
Infinite Layer ◽  
Layered Thin Film

AbstractSuperlattice structures, consisting of SrCuO2, (Sr,Ca)CuO2, and BaCuO2 layers in the tetragonal, "infinite layer" crystal structure, have been grown by pulsed-laser deposition (PLD). Superlattice chemical modulation is observed for structures with component layers as thin as a single unit cell (~3.4 Å), indicating that unit-cell control of (Sr,Ca)CuO2 growth is possible using conventional pulsed-laser deposition over a wide oxygen pressure regime. X-ray diffraction intensity oscillations, due to the finite thickness of the film, indicate that these films are extremely flat with a thickness variation of only ~20 Å over a length scale of several thousand angstroms. Using the constraint of epitaxy to grow metastable cuprates in the infinite layer structure, novel high-temperature superconducting structural families have been formed. IN particular, epitaxially-stabilized SrCuO2/BaCuO2 superlattices, grown by sequentially depositing on lattice-matched (100) SrTiO3 from BaCuO2 and SrCuO2 ablation targets in a PLD system, show metallic conductivity and superconductivity at Tc(onset) ~70 K. these results show that pulsed-laser deposition and epitaxial stabilization have been used to effectively "engineer" artificially-layered thin-film materials.

scholarly journals Нелинейные интерфейсные волны в трехслойной оптической структуре с отличающимися характеристиками слоев и внутренней самофокусировкой

2019 ◽  
Vol 127 (7) ◽  
pp. 159
Author(s):  
С.Е. Савотченко
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Nonlinear Response ◽  
Finite Thickness ◽  
Mathematical Formulation ◽  
Localization Length ◽  
Refractive Indices ◽  
Characteristic Distance ◽  
Interface Waves

AbstractA model of a trilayered optical structure, the plane-parallel boundary of which possesses its own nonlinear properties, is considered. The inner layer with a finite thickness is an optically transparent medium with Kerr self-focusing nonlinearity, which is in contact with linear half-spaces from the outer surface that are characterized by refractive indices independent of the electric field strength amplitude. Refractive indices in the layer interfaces within infinitely small thicknesses are approximated by the dependence that includes Dirac’s delta function. It is shown that the mathematical formulation of the model boils down to a nonlinear Schrödinger equation with a nonlinear self-consistent potential. It is established that two types of nonlinear localized waves of the electric field strength perturbations can propagate along the layers in the considered trilayered structure. Dispersion relations of the interface waves that allow one to determine the propagation constant and decrements of their spatial attenuation in linear half-spaces as a function of the system parameters are derived. Conditions for localization of a luminous flux along the layer interfaces are analyzed in relation to the sign of the layer parameters. It is shown that the characteristic distance of the field localization linearly depends on the interface nonlinear response parameter. It is established that the characteristic localization distance is shortened in the case of a positive nonlinear response in comparison with the localization length when interfaces do not interact with the field and lengthened in the case of a negative nonlinear response.

scholarly journals Two Types of Localized States in a Photonic Crystal Bounded by an Epsilon Near Zero Nanocomposite

2018 ◽  
Author(s):  
Rashid G. Bikbaev ◽  
Stepan Ya. Vetrov ◽  
Ivan V. Timofeev
Keyword(s):  
Photonic Crystal ◽  
Defect Mode ◽  
Localized States ◽  
Simultaneous Formation ◽  
One Dimensional ◽  
Nanocomposite Layer ◽  
Localized State ◽  
Plasmon Polariton ◽  
Field Localization ◽  
First Time

The spectral properties of a one-dimensional photonic crystal bounded by a resonant absorbing nanocomposite layer with the near-zero permittivity have been studied. The problem of calculating the transmittance, reflectance, and absorptance spectra of such structures at the normal and oblique incidence of light has been solved. It is shown that, depending on the permittivity sign near zero, the nanocomposite is characterized by either metallic or dielectric properties. For the first time, the possibility of simultaneous formation of the Tamm plasmon polariton at the photonic crystal/metallic nanocomposite interface and the localized state similar to the defect mode with the field intensity maximum inside the dielectric nanocomposite layer is demonstrated. Specific features of field localization at the Tamm plasmon polariton and defect mode frequencies are analyzed.

Localized states in symmetric three-layered structure consisting of linear layer between focusing media separated by interfaces with nonlinear response

2019 ◽  
Vol 33 (11) ◽  
pp. 1850127
Author(s):  
S. E. Savotchenko
Keyword(s):  
Nonlinear Response ◽  
Mathematical Formulation ◽  
Localized States ◽  
Stationary States ◽  
Nonlinear Media ◽  
One Dimensional ◽  
Symmetric Structure ◽  
Linear Layer ◽  
Dimensional Boundary ◽  
Interface Parameters

We analyze the localization in three-layered symmetric structure consisting of linear layer between focusing nonlinear media separated by nonlinear interfaces. The mathematical formulation of the model is a one-dimensional boundary value problem for the nonlinear Schrödinger equation. We find nonlinear localized states of two types of symmetry. We derive the energies of obtained stationary states in explicit form. We obtain the localization energies as exact solutions of dispersion equations choosing the amplitude of the interface oscillations as a free parameter. We analyze the conditions of their existence depending on the combination of signs of interface parameters.

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