Particularities of the Formation of Localized States near a Planar Defect in Media with an Abruptly Changing Defocusing Nonlinear Response

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.

Download Full-text

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

Физика твердого тела ◽

10.21883/ftt.2020.03.49013.534 ◽

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.

Download Full-text

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

Физика твердого тела ◽

10.21883/ftt.2019.03.47253.288 ◽

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.

Download Full-text

LOCALIZED STATES AND BAND STRUCTURE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1972304 ◽

1972 ◽

Vol 33 (C3) ◽

pp. C3-21-C3-25 ◽

Cited By ~ 3

Author(s):

F. BASSANI

Keyword(s):

Band Structure ◽

Localized States

Download Full-text

COMPARISON OF OPTICALLY INDUCED LOCALIZED STATES IN CHALCOGENIDE GLASSES AND THEIR CRYSTALLINE COUNTERPARTS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1981482 ◽

1981 ◽

Vol 42 (C4) ◽

pp. C4-383-C4-386 ◽

Cited By ~ 4

Author(s):

S. G. Bishop ◽

B. V. Shanabrook ◽

U. Strom ◽

P. C. Taylor

Keyword(s):

Chalcogenide Glasses ◽

Localized States ◽

Optically Induced

Download Full-text

Low-Temperature Operation of Green, Blue and UV InGaN/GaN Multiple-Quantum-Well Light-Emitting Diodes

MRS Proceedings ◽

10.1557/proc-764-c5.5 ◽

2003 ◽

Vol 764 ◽

Author(s):

X. A. Cao ◽

S. F. LeBoeuf ◽

J. L. Garrett ◽

A. Ebong ◽

L. B. Rowland ◽

...

Keyword(s):

Quantum Well ◽

Light Emitting Diodes ◽

Multiple Quantum Well ◽

Light Output ◽

Localized States ◽

Multiple Quantum ◽

Nonradiative Recombination ◽

Light Emitting ◽

Temperature Range ◽

Green Leds

Absract:Temperature-dependent electroluminescence (EL) of InGaN/GaN multiple-quantum-well light-emitting diodes (LEDs) with peak emission energies ranging from 2.3 eV (green) to 3.3 eV (UV) has been studied over a wide temperature range (5-300 K). As the temperature is decreased from 300 K to 150 K, the EL intensity increases in all devices due to reduced nonradiative recombination and improved carrier confinement. However, LED operation at lower temperatures (150-5 K) is a strong function of In ratio in the active layer. For the green LEDs, emission intensity increases monotonically in the whole temperature range, while for the blue and UV LEDs, a remarkable decrease of the light output was observed, accompanied by a large redshift of the peak energy. The discrepancy can be attributed to various amounts of localization states caused by In composition fluctuation in the QW active regions. Based on a rate equation analysis, we find that the densities of the localized states in the green LEDs are more than two orders of magnitude higher than that in the UV LED. The large number of localized states in the green LEDs are crucial to maintain high-efficiency carrier capture at low temperatures.

Download Full-text