共查询到20条相似文献,搜索用时 296 毫秒
1.
D. Mihalache D. Mazilu F. Lederer 《The European physical journal. Special topics》2009,173(1):255-266
In the framework of the continuous-discrete cubic-quintic Ginzburg-Landau model, spatiotemporal dissipative solitons which
are highly confined inside two-dimensional photonic lattices are found numerically. The domains of existence in the relevant
parameter space, of in-phase (unstaggered) on-site (single-peaked), inter-site (double-peaked), and flat-top-like (four-peaked)
spatiotemporal dissipative solitons are determined. We show that the on-site solitons are stable in the whole domain of their
existence and we find the stability domains of both inter-site and flat-top-like solitons. We describe the complex instability-induced
scenarios of the dynamics of spatiotemporal discrete Ginzburg-Landau solitons in two-dimensional photonic lattices. 相似文献
2.
Dynamical properties of discrete solitons in nonlinear Schr?dinger lattices with saturable nonlinearity are studied in the framework of the one-dimensional discrete Vinetskii-Kukhtarev model. Two stationary strongly localized modes, centered on site (A) and between two neighboring sites (B), are obtained. The associated Peierls-Nabarro potential is bounded and has multiple zeros indicating strong implications on the stability and dynamics of the localized modes. Besides a stable propagation of mode A, a stable propagation of mode B is also possible. The enhanced ability of the large power solitons to move across the lattice is pointed out and numerically verified. 相似文献
3.
Manuel G. Velarde Alexander P. Chetverikov Werner Ebeling Sergey V. Dmitriev Victor D. Lakhno 《The European Physical Journal B - Condensed Matter and Complex Systems》2016,89(10):233
The excitation of solitons and discrete breathers (pinned or otherwise, also known asintrinsic localized modes, DB/ILM) in a one-dimensional lattice, also denoted as a chain,is considered when both on-site and inter-site vibrations, coupled together, are governedby the empirical Morse interaction. We focus attention on the transformation of the formerinto the latter as the relative strength of the on-site potential to that of theinter-site potential is increased. 相似文献
4.
Qiongtao Xie 《Central European Journal of Physics》2014,12(12):830-835
We present exact analytical results for bright and dark solitons in a type of one-dimensional spatially inhomogeneous nonlinearity. We show that the competition between a homogeneous self-defocusing (SDF) nonlinearity and a localized self-focusing (SF) nonlinearity supports stable fundamental bright solitons. For a specific choice of the nonlinear parameters, exact analytical solutions for fundamental bright solitons have been obtained. By applying both variational approximation and Vakhitov-Kolokolov stability criterion, it is found that exact fundamental bright solitons are stable. Our analytical results are also confirmed numerically. Additionally, we show that a homogeneous SF nonlinearity modulated by a localized SF nonlinearity allows the existence of exact dark solitons, for certain special cases of nonlinear parameters. By making use of linear stability analysis and direct numerical simulation, it is found that these exact dark solitons are linearly unstable. 相似文献
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M. Stojanovi?A. Maluckov Lj. Had?ievskiB.A. Malomed 《Physica D: Nonlinear Phenomena》2011,240(18):1489-1496
Fundamental solitons pinned to the interface between three semi-infinite one-dimensional nonlinear dynamical chains, coupled at a single site, are investigated. The light propagation in the respective system with the self-attractive on-site cubic nonlinearity, which can be implemented as an array of nonlinear optical waveguides, is modeled by the system of three discrete nonlinear Schrödinger equations. The formation, stability and dynamics of symmetric and asymmetric fundamental solitons centered at the interface are investigated analytically by means of the variational approximation (VA) and in a numerical form. The VA predicts that two asymmetric and two antisymmetric branches exist in the entire parameter space, while four asymmetric modes and the symmetric one can be found below some critical value of the inter-lattice coupling parameter—actually, past the symmetry-breaking bifurcation. At this bifurcation point, the symmetric branch is destabilized and two new asymmetric soliton branches appear, one stable and the other unstable. In this area, the antisymmetric branch changes its character, getting stabilized against oscillatory perturbations. In direct simulations, unstable symmetric modes radiate a part of their power, staying trapped around the interface. Highly unstable asymmetric modes transform into localized breathers traveling from the interface region across the lattice without significant power loss. 相似文献
7.
We propose the interesting results that a bright and dark soliton pulse can be localized within a nonlinear nano-waveguide. The system consists of nonlinear micro- and nano-ring resonators, whereas the soliton pulse can be input into the system and trapped within the nano-waveguide. A soliton input is chopped by the nonlinear effects known as chaos into smaller pulses. The required pulse is filtered and amplified, which can be controlled and localized within the nano-waveguide. The localized bright and dark solitons are trapped within a nano-waveguide by controlling the nano-waveguide input power, which means that the photons trapping is controlled by light. 相似文献
8.
Intrinsic localized mode (ILM) is spatially localized and temporally periodic oscillation in nonlinear coupled oscillators. We numerically investigate the dynamical stability of ILMs in a microcantilever array, in which ILMs were experimentally observed by Sato et al. It is found that the stability change of ILMs is due to the ratio in nonlinear potentials. This phenomenon also occurs in the array without harmonic potentials. Consequently, the stability of ILMs substantially depends on the ratio in nonlinear on-site and inter-site potentials. 相似文献
9.
The formation of unstaggered localized modes in dynamical lattices can be supported by the interplay of discreteness and nonlinearity with a finite relaxation time. In rapidly responding nonlinear media, on-site discrete solitons are stable, and their broad intersite counterparts are marginally stable, featuring a virtually vanishing real instability eigenvalue. The solitons become unstable in the case of the slowly relaxing nonlinearity. The character of the instability alters with the increase of the delay time, which leads to a change in the dynamics of unstable discrete solitons. They form robust localized breathers in rapidly relaxing media, and decay into oscillatory diffractive pattern in the lattices with a slow nonlinear response. Marginally stable solitons can freely move across the lattice. 相似文献
10.
SBN:Cr晶体中孤子诱导的实时平面光波导及其导光特性分析 总被引:2,自引:1,他引:1
通过数值模拟和实验对SBN:Cr晶体中的(1+1)维亮屏蔽空间孤子及其诱导的实时平面光波导的导光特性进行了研究.采用分步束传播法和Petviashvili迭代法对(1+1)维亮屏蔽空间孤子的特性进行了模拟.通过求解本征方程,对孤子诱导平面波导中存在的导波模式进行了数值求解.采用633 nm的He-Ne激光作为孤子诱导光束,532 nm的半导体泵浦的固体激光作为探测光,在固液同成分的SBN:Cr晶体中进行了实验研究.实验结果和数值模拟的结果符合的很好.而且结果表明SBN:Cr晶体中红光诱导的波导可以作为实时光波导. 相似文献
11.
We discuss the formation of guided modes localized at the interface separating two different periodic photonic lattices. Employing the effective discrete model, we analyze linear and nonlinear interface modes and also predict the existence of stable interface solitons including the hybrid staggered/unstaggered lattice solitons with the tails belonging to spectral gaps of different types. 相似文献
12.
A multiple scales technique is employed to solve the fluid-Maxwell equations describing a weakly nonlinear circularly polarized electromagnetic pulse in magnetized plasma. A nonlinear Schrödinger-type (NLS) equation is shown to govern the amplitude of the vector potential. The conditions for modulational instability and for the existence of various types of localized envelope modes are investigated in terms of relevant parameters. Right-hand circularly polarized (RCP) waves are shown to be modulationally unstable regardless of the value of the ambient magnetic field and propagate as bright-type solitons. The same is true for left-hand circularly polarized (LCP) waves in a weakly to moderately magnetized plasma. In other parameter regions, LCP waves are stable in strongly magnetized plasmas and may propagate as dark-type solitons (electric field holes). The evolution of envelope solitons is analyzed numerically, and it is shown that solitons propagate in magnetized plasma without any essential change in amplitude and shape. 相似文献
13.
The existence of stationary wave packets in the nonlinear Kerr media with an imaginary harmonic potential and a linear gain is investigated. By employing a variational approach the existence of stable bright solitons is shown for the case of a defocusing nonlinearity. In focusing nonlinear media, the bright solitons have been shown to be unstable. The predictions of variational approach are confirmed by numerical simulations of the full modified NLS equation. The predicted stationary localized wave packets can be observed in a quasi-one-dimensional BEC with an imaginary optical potential and atoms feeding. 相似文献
14.
Alain Bertrand Togueu Motcheyo Clément Tchawoua Martin Siewe Siewe Joel Durel Tchinang Tchameu 《Physics letters. A》2011,375(7):1104-1109
We show that a discrete electrical transmission line, such as a Band-pass filter is modeled by the Salerno equation at the upper cutoff mode. Special interest is paid to the investigation of stationary localized solutions supported by this equation for some given experimental parameters. Applying a map approach, the profiles of single and two bright solitons are obtained. Linear stability and direct numerical simulations are performed and the results show that a single bright soliton is stable while two bright ones are unstable and lead to a single bright soliton. Finally, we show that the lifespan of two hump solitons increases depending on the length thrust range of the kicked initial condition. 相似文献
15.
We investigate the stability and phase transition of localized modes in Bose–Einstein Condensates (BECs) in an optical lattice with the discrete nonlinear Schrödinger model by considering both two- and three-body interactions. We find that there are three types of localized modes, bright discrete breather (DB), discrete kink (DK), and multi-breather (MUB). Moreover, both two- and three-body on-site repulsive interactions can stabilize DB, while on-site attractive three-body interactions destabilize it. There is a critical value for the three-body interaction with which both DK and MUB become the most stable ones. We give analytically the energy thresholds for the destabilization of localized states and find that they are unstable (stable) when the total energy of the system is higher (lower) than the thresholds. The stability and dynamics characters of DB and MUB are general for extended lattice systems. Our result is useful for the blocking, filtering, and transfer of the norm in nonlinear lattices for BECs with both two- and three-body interactions. 相似文献
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Alexander TJ Kivshar YS Buryak AV Sammut RA 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》2000,61(2):2042-2049
We analyze two-component spatial optical vortex solitons supported by parametric wave mixing processes in a nonlinear bulk medium. We study two distinct cases of such localized waves, namely, parametric vortex solitons due to phase-matched second-harmonic generation in an optical medium with competing quadratic and cubic nonlinear response, and vortex solitons in the presence of third-harmonic generation in a cubic medium. We find, analytically and numerically, the structure of two-component vortex solitons, and also investigate modulational instability of their plane-wave background. In particular, we predict and analyze in detail novel types of vortex solitons, a "halo-vortex," consisting of a two-component vortex core surrounded by a bright ring of its harmonic field, and a "ring-vortex" soliton which is a vortex in a harmonic field that guides a ring-like localized mode of the fundamental-frequency field. 相似文献
18.
We study experimentally nonlinear localization effects in optically induced gratings created by interfering plane waves in a photorefractive crystal. We demonstrate the generation of spatial bright solitons similar to those observed in arrays of coupled optical waveguides. We also create pairs of out-of-phase solitons, which resemble twisted localized states in nonlinear lattices. 相似文献
19.
Optical solitons supported by finite waveguide lattices with diffusive nonlocal nonlinearity
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Changming Huang 《中国物理 B》2021,30(12):124204-124204
We investigate the properties of fundamental, multi-peak, and multi-peaked twisted solitons in three types of finite waveguide lattices imprinted in photorefractive media with asymmetrical diffusion nonlinearity. Two opposite soliton self-bending signals are considered for different families of solitons. Power thresholdless fundamental and multi-peaked solitons are stable in the low power region. The existence domain of two-peaked twisted solitons can be changed by the soliton self-bending signals. When solitons tend to self-bend toward the waveguide lattice, stable two-peaked twisted solitons can be found in a larger region in the middle of their existence region. Three-peaked twisted solitons are stable in the lower (upper) cutoff region for a shallow (deep) lattice depth. Our results provide an effective guidance for revealing the soliton characteristics supported by a finite waveguide lattice with diffusive nonlocal nonlinearity. 相似文献
20.
Based on the temperature dependence of two-wave mixing, temperature effects on the dynamical evolution and stability of rigid screening (RS) bright solitons in a photorefractive dissipative system based on two-wave mixing have been investigated numerically. Our results indicate that the stability of bright RS solitons depends strongly on the crystal temperature. The RS solitons are stable to small temperature perturbations. They will not evolve into stable rigid screening solitons, however, and their intensity and width vary with the propagation distance if the temperature deviation is large enough. The potential applications of the temperature properties of these RS solitons in optical attenuators or repeaters are discussed. 相似文献