Breather and its interaction with rogue wave of the coupled modified nonlinear Schrodinger equation

We investigate the coupled modified nonlinear Schr?dinger equation.Breather solutions are constructed through the traditional Darboux transformation with nonzero plane-wave solutions.To obtain the higher-order localized wave solution,the N-fold generalized Darboux transformation is given.Under the condition that the characteristic equation admits a double-root,we present the expression of the first-order interactional solution.Then we graphically analyze the dynamics of the breather and rogue wave.Due to the simultaneous existence of nonlinear and self-steepening terms in the equation,different profiles in two components for the breathers are presented.

Nondegenerate solitons of the(2+1)-dimensional coupled nonlinear Schrodinger equations with variable coefficients in nonlinear optical fibers

We derive the multi-hump nondegenerate solitons for the(2+1)-dimensional coupled nonlinear Schrodinger equations with propagation distance dependent diffraction,nonlinearity and gain(loss)using the developing Hirota bilinear method,and analyze the dynamical behaviors of these nondegenerate solitons.The results show that the shapes of the nondegenerate solitons are controllable by selecting different wave numbers,varying diffraction and nonlinearity parameters.In addition,when all the variable coefficients are chosen to be constant,the solutions obtained in this study reduce to the shape-preserving nondegenerate solitons.Finally,it is found that the nondegenerate two-soliton solutions can be bounded to form a double-hump two-soliton molecule after making the velocity of one double-hump soliton resonate with that of the other one.

A high order energy preserving scheme for the strongly coupled nonlinear Schr¨odinger system

A high order energy preserving scheme for a strongly coupled nonlinear Schrōdinger system is roposed by using the average vector field method. The high order energy preserving scheme is applied to simulate the soliton evolution of the strongly coupled Schrōdinger system. Numerical results show that the high order energy preserving scheme can well simulate the soliton evolution, moreover, it preserves the discrete energy of the strongly coupled nonlinear Schrōdinger system exactly.

Soliton, Breather and Rogue Wave Solutions for the Nonlinear Schrdinger Equation Coupled to a Multiple Self-Induced Transparency System

We derive an N-fold Darboux transformation for the nonlinear Schrdinger equation coupled to a multiple selfinduced transparency system, which is applicable to optical fiber communications in the erbium-doped medium.The N-soliton, N-breather and N th-order rogue wave solutions in the compact determinant representations are derived using the Darboux transformation and limit technique. Dynamics of such solutions from the first-to second-order ones are shown.

Localized waves of the coupled cubic–quintic nonlinear Schrdinger equations in nonlinear optics

We investigate some novel localized waves on the plane wave background in the coupled cubic-quintic nonlinear Schrdinger （CCQNLS） equations through the generalized Darboux transformation （DT）. A special vector solution of the Lax pair of the CCQNLS system is elaborately constructed, based on the vector solution, various types of higher-order localized wave solutions of the CCQNLS system are constructed via the generalized DT. These abundant and novel localized waves constructed in the CCQNLS system include higher-order rogue waves, higher-order rogues interacting with multi-soliton or multi-breather separately. The first-and second-order semi-rational localized waves including several free parameters are mainly discussed：（i） the semi-rational solutions degenerate to the first-and second-order vector rogue wave solutions; （ii） hybrid solutions between a first-order rogue wave and a dark or bright soliton, a second-order rogue wave and two dark or bright solitons; （iii） hybrid solutions between a first-order rogue wave and a breather, a second-order rogue wave and two breathers. Some interesting and appealing dynamic properties of these types of localized waves are demonstrated, for example, these nonlinear waves merge with each other markedly by increasing the absolute value of α. These results further uncover some striking dynamic structures in the CCQNLS system.

Novel exact solutions of coupled nonlinear Schro¨dinger equations with time–space modulation

We construct various novel exact solutions of two coupled dynamical nonlinear Schrōdinger equations. Based on the similarity transformation, we reduce the coupled nonlinear Schrōdinger equations with time-and space-dependent potentials, nonlinearities, and gain or loss to the coupled dynamical nonlinear Schrrdinger equations. Some special types of non-travelling wave solutions, such as periodic, resonant, and quasiperiodically oscillating solitons, are used to exhibit the wave propagations by choosing some arbitrary functions. Our results show that the number of the localized wave of one component is always twice that of the other one. In addition, the stability analysis of the solutions is discussed numerically.

Solving coupled nonlinear Schrodinger equations via a direct discontinuous Galerkin method

In this work, we present the direct discontinuous Galerkin （DDG） method for the one-dimensional coupled nonlinear Schr5dinger （CNLS） equation. We prove that the new discontinuous Galerkin method preserves the discrete mass conservations corresponding to the properties of the CNLS system. The ordinary differential equations obtained by the DDG space discretization is solved via a third-order stabilized Runge Kutta method. Numerical experiments show that the new DDG scheme gives stable and less diffusive results and has excellent long-time numerical behaviors for the CNLS equations.

Quaternion Approach to Solve Coupled Nonlinear Schrdinger Equation and Crosstalk of Quarter-Phase-Shift-Key Signals in Polarization Multiplexing Systems

The quaternion approach to solve the coupled nonlinear Schrodinger equations （CNSEs） in fibers is proposed, converting the CNSEs to a single variable equation by using a conception of eigen-quaternion of coupled quater- nion. The crosstalk of quarter-phase-shift-key signals caused by fiber nonlinearity in polarization multiplexing systems with 100 Cbps bit-rate is investigated and simulated. The results demonstrate that the crosstalk is like a rotated ghosting of input constellation. For the 50 km conventional fiber link, when the total power is less than 4roW, the crosstalk effect can be neglected; when the power is larger than 20roW, the crosstalk is very obvious. In addition, the crosstalk can not be detected according to the output eye diagram and state of polarization in Poincare sphere in the trunk fiber, making it difficult for the monitoring of optical trunk link.

New Exact Solutions for the Coupled Nonlinear Schrödinger Equations with Variable Coefficients

In this paper, coupled nonlinear Schrödinger equations with variable coefficients are studied, which can be used to describe the interaction among the modes in nonlinear optics and Bose-Einstein condensation. Some novel bright-dark solitons and dark-dark solitons are obtained by modified Sine-Gordon equation method. Moreover, some figures are provided to illustrate how the soliton solutions propagation is determined by the different values of the variable group velocity dispersion terms, which can be used to model various phenomena.

应用全新G'/(G+G')展开方法求解广义非线性Schrdinger方程和耦合非线性Schrdinger方程组

研究了一种全新的G'/(G+G')展开方法,并应用这种方法讨论了广义非线性Schrdinger方程和一类耦合非线性Schrdinger方程组新形式的精确解,包括双曲余切函数解、余切函数解和有理函数解.全新G'/(G+G')展开方法不但直接而有效地求出方程的新精确解,而且扩大了解的范围,这种新方法对于研究偏微分方程具有广泛的应用意义.

一类耦合非线性Schrdinger方程的Painlevé性质、严格解及其在大气重力波中的应用

讨论了大气科学里的一类耦合非线性Schrdinger方程的Painlevé可积性和严格解.并给出了这个耦合方程通过Painlevé性质检测的参数条件.应用椭圆余弦函数展开法,得到了这个耦合非线性Schrdinger方程的20个周期椭圆余弦波解.这些严格解被用应用于解释大气重力波的产生和传输机制.

用G′/G-展开法求解耦合离散Schrdinger方程组的精确解

依据齐次平衡原则,利用G′/G-展开法求解出耦合离散非线性Schrdinger方程组的双曲函数形式孤波解、三角函数形式周期波解和有理函数形式行波解,这些精确解含有较多的任意参数。

扰动非线性Schrdinger方程组的动力性态

研究具周期边界条件的扰动非线性Schr dinger方程组的动力性态,首先,在常值平面上用线性算子的谱对扰动和未扰动系统进行动力性态分析。

新的变系数可积耦合非线性Schrdinger方程及其孤子解

基于延拓结构和Hirota双线性方法研究了广义的变系数耦合非线性Schrdinger方程.首先导出了3组新的变系数可积耦合非线性Schrdinger方程及其线性谱问题(Lax对),然后利用Hirota双线性方法给出了它们的单、双向量孤子解.这些向量孤子解在光孤子通讯中有重要的应用.

耦合非线性Schrdinger方程组的Neumann问题

该文考虑一类耦合椭圆型非线性Schr(o|¨)dinger方程组的Neumann问题极小能量解(基态解)的存在性和集中性质.主要研究极小能量解的尖点,即最大值点的位置.利用Lin TaiChia和WeiJuncheng研究Dirichlet问题的方法,该文首先得到了相应Neumann问题的极小能量解的存在性.当相当于Planck常数的小参数趋于零时,该文证明了极小能量解的尖点向定义区域的边界靠近,并且能量集中在这些尖点处.另外,方程组解的两个分支解相互吸引或排斥时,它们的尖点也相互吸引或排斥.

自治耦合格点非线性Schrdinger方程组的一致吸引子及熵的估计

讨论一类自治耦合格点非线性Schrodinger方程组解的渐近行为.证明该格点方程组在适当意义下存在一致吸引子,并给出一致吸引子Kolmogorov-ε熵的上界估计.

Solitary wave solutions for the variable-coefficient coupled nonlinear Schrödinger equations and Davey-Stewartson system using modified sine-Gordon equation method

In this study,the sine-Gordon equation method is modified to deal with variable-coefficient systems containing imaginary parts,such as nonlinear Schrödinger systems.These are of considerable importance in many fields of research,including ocean engineering and optics.As an example,we apply the modified method to variable-coefficient coupled nonlinear Schrödinger equations and Davey-Stewartson system with variable coefficients,treating them as one-dimensional and two-dimensional systems,respectively.As a result of this application,novel solitary wave solutions are obtained for both cases.Moreover,some figures are provided to illustrate how the solitary wave propagation is determined by the different values of the variable group velocity dispersion terms,which can be used to model various phenomena.

耦合非线性Schrdinger系统的多辛差分格式

近年来,Bridges等人在Hamiltonian力学意义下,直接把有限维Hamiltonian系统推广到无穷维,通过引入新的函数坐标,使得偏微分方程在时间和空间的各个方向上都有各自不同的有限维辛结构,这样原偏微分方程就由各个有限维辛结构以及右端的梯度函数决定,称这样的方程为多辛Hamiltonian系统.多辛Hamiltonian系统满足多辛守恒定律,满足多辛Hamiltonian系统的多辛守恒律的离散算法称为多辛算法.以耦合非线性Schr dinger方程为例,研究无穷维Hamiltonian系统的多辛算法,验证了两孤立子碰撞后会发生相互通过、反射及融合现象.

Solutions of the 1D Coupled Nonlinear Schrodinger Equations by the CIP-BS Method

In this paper,we present solutions for the one-dimensional coupled nonlinear Schrödinger(CNLS)equations by the Constrained Interpolation Profile-Basis Set(CIP-BS)method.This method uses a simple polynomial basis set,by which physical quantities are approximated with their values and derivatives associated with grid points.Nonlinear operations on functions are carried out in the framework of differential algebra.Then,by introducing scalar products and requiring the residue to be orthogonal to the basis,the linear and nonlinear partial differential equations are reduced to ordinary differential equations for values and spatial derivatives.The method gives stable,less diffusive,and accurate results for the CNLS equations.

Numerical Solutions of Coupled Nonlinear Schrödinger Equations by Orthogonal Spline Collocation Method

In this paper,we present the use of the orthogonal spline collocation method for the semi-discretization scheme of the one-dimensional coupled nonlinear Schrödinger equations.This method uses the Hermite basis functions,by which physical quantities are approximatedwith their values and derivatives associatedwith Gaussian points.The convergence rate with order O(h4+t2)and the stability of the scheme are proved.Conservation properties are shown in both theory and practice.Extensive numerical experiments are presented to validate the numerical study under consideration.