Search results for "SOLITONS"
showing 10 items of 401 documents
Controlled Observation of a Nonequilibrium Ising-Bloch Transition in a Nonlinear Optical Cavity
2004
We describe the controlled observation of the nonequilibrium Ising-Bloch transition in a broad area nonlinear optical cavity, namely, a quasi-1D single longitudinal-mode photorefractive oscilator in a degenerate four-wave mixing configuration. Our experimental technique allows for the controlled injection of the domain walls. We use cavity detuning as control parameter and find that both Ising and Bloch walls can exist for the same detuning values within a certain interval of detunings, i.e., the Ising-Bloch transition is hysteretic in our case. A complex Ginzburg-Landau model is used for supporting the observations.
Optical solitons in erbium doped fibers with higher order effects
2000
Abstract We consider the coupled system of higher order nonlinear Schrodinger equation and Maxwell–Bloch (HNLS–MB) equations, which governs the nonlinear wave propagation in erbium doped optical waveguides in presence of important higher order effects. We present the Lax pair and using Backlund transformation exact soliton solutions are generated.
Domain wall dynamics in an optical Kerr cavity
2004
An anisotropic (dichroic) optical cavity containing a self-focusing Kerr medium is shown to display a bifurcation between static --Ising-- and moving --Bloch-- domain walls, the so-called nonequilibrium Ising-Bloch transition (NIB). Bloch walls can show regular or irregular temporal behaviour, in particular, bursting and spiking. These phenomena are interpreted in terms of the spatio-temporal dynamics of the extended patterns connected by the wall, which display complex dynamical behaviour as well. Domain wall interaction, including the formation of bound states is also addressed.
Kinks and antikinks of buckled graphene: A testing ground for phi^4 field model
2017
Kinks and antikinks of the classical ${\ensuremath{\varphi}}^{4}$ field model are topological solutions connecting its two distinct ground states. Here we establish an analogy between the excitations of a long graphene nanoribbon buckled in the transverse direction and ${\ensuremath{\varphi}}^{4}$ model results. Using molecular dynamics simulations, we investigated the dynamics of a buckled graphene nanoribbon with a single kink and with a kink-antikink pair. Several features of the ${\ensuremath{\varphi}}^{4}$ model have been observed including the kink-antikink capture at low energies, kink-antikink reflection at high energies, and a bounce resonance. Our results pave the way towards the …
The Impact of a Finite Waveguide Work Function on Resonant Tunneling
2021
To describe electron transport in a waveguide, we assume that the electron wave functions vanish at the waveguide boundary. This means that, being in the waveguide, an electron can not cross the waveguide boundary because of the infinite potential barrier. In reality, the assumption has never been fulfilled: generally, electrons can penetrate through the waveguide boundary and go some distance away from the waveguide. Therefore, we have to clarify how this phenomenon affects the resonant tunneling.
Resonant Plasmon-Soliton Interaction
2008
We describe an effective resonant interaction between two localized wave modes of different nature: a plasmon-polariton at a metal surface and a self-focusing beam (spatial soliton) in a non-linear dielectric medium. Propagating in the same direction, they represent an exotic coupled-waveguide system, where the resonant interaction is controlled by the soliton amplitude. This non-linear system manifests hybridized plasmon-soliton eigenmodes, mutual conversion, and non-adiabatic switching, which offer exciting opportunities for manipulation of plasmons via spatial solitons.
Impurity effects on soliton dynamics in planar ferromagnets
1993
Abstract We investigate numerically the dynamics of solitons in a ferromagnetic spin chain and we show that the sine-Gordon approximation provides only a poor description of the solitary excitations in the presence of impurities. Depending on their energy and the strength of the impurity, solitons can be reflected or transmitted. When they are reflected, they can suffer abrupt changes in velocity, which are associated to the switch from one soliton branch to another. In some cases the scattering by an impurity can excite an internal mode of the soliton, which is able to store some energy and modify the output of the scattering.
Vortex solitons in photonic crystal fibers
2003
We demonstrate the existence of vortex soliton solutions in photonic crystal fibers. We analyze the role played by the photonic crystal fiber defect in the generation of optical vortices. An analytical prediction for the angular dependence of the amplitude and phase of the vortex solution based on group theory is also provided. Furthermore, all the analysis is performed in the non-paraxial regime.
Watch-hand-like optical rogue waves in three-wave interactions
2015
11 págs.; 6 figs.; OCIS codes: (190.3100) Instabilities and chaos; (190.5530) Pulse propagation and temporal solitons; (190.4410) Nonlinear optics, parametric processes.
Multipole solitary wave solutions of the higher-order nonlinear Schrödinger equation with quintic non-Kerr terms
2013
We consider a high-order nonlinear Schrodinger (HNLS) equation with third- and fourth-order dispersions, quintic non-Kerr terms, self steepening, and self-frequency-shift effects. The model applies to the description of ultrashort optical pulse propagation in highly nonlinear media. We propose a complex envelope function ansatz composed of single bright, single dark and the product of bright and dark solitary waves that allows us to obtain analytically different shapes of solitary wave solutions. Parametric conditions for the existence and uniqueness of such solitary waves are presented. The solutions comprise fundamental solitons, kink and anti-kink solitons, W-shaped, dipole, tripole, and…