Solitary Waves for Cubic-Quintic Nonlinear Schroedinger Equation with Variable Coefficients

The cubic-quintic nonlinear Schroedinger equation （CQNLS） plays important parts in the optical fiber and the nuclear hydrodynamics. By using the homogeneous balance principle, the bell type, kink type, algebraic solitary waves, and trigonometric traveling waves for the cubic-quintic nonlinear Schroedinger equation with variable coefficients （vCQNLS） are derived with the aid of a set of subsidiary high-order ordinary differential equations （sub-equations for short）. The method used in this paper might help one to derive the exact solutions for the other high-order nonlinear evolution equations, and shows the new application of the homogeneous balance principle.

Spatiotemporal Similaritons in (3+l)-Dimensional Inhomogeneous Nonlinear Medium with Cubic-Quintic Nonlinearity

We obtain exact spatiotemporal similaritons to a （3＋ l）-dimensional inhomogeneous nonlinear Schrodinger equation, which describes the propagation of optical pulses in a cubic-quintic nonlinearity medium with distributed dispersion and gain. A one-to-one correspondence between such self-similar waves and solutions of the elliptic equation is found when a certain compatibility condition is satisfied. Based on exact solutions, we discuss evolutional behaviors of self-similar cnoidal waves and chirped similaritons in two kind of typicai soliton control systems. Moreover, the comparison between chirped similaritons and chirp-free solitons is given.

Self-Similar Solutions of Variable-Coefficient Cubic-Quintic Nonlinear Schr(o|¨)dinger Equation with an External Potential

An improved homogeneous balance principle and self-similar solutions to the cubic-quintic nonlinear Schroedinger and impose constraints on the functions describing dispersion, self-similar waves are presented.

Exact Meromorphic Stationary Solutions of the Cubic-Quintic Swift-Hohenberg Equation

In this paper, we study an ODE of the form b0u（4）＋b1u′′＋b2u＋b3u3＋b4u5=0, ′= d/dz＇ , which includes, as a special case, the stationary case of the cubic-quintic Swift-Hohenberg equation. Based on Nevanlinna theory and Painleve analysis, we first show that all its meromorphic solutions are elliptic or degenerate elliptic. Then we obtain them all explicitly by the method introduced in [7].

Hybrid Dispersive Optical Solitons in Nonlinear Cubic-Quintic-Septic Schrödinger Equation

Certain hybrid prototypes of dispersive optical solitons that we are looking for can correspond to new or future behaviors, observable or not, developed or will be developed by optical media that present the cubic-quintic-septic law coupled, with strong dispersions. The equation considered for this purpose is that of non-linear Schrödinger. The solutions are obtained using the Bogning-Djeumen Tchaho-Kofané method extended to the new implicit Bogning’ functions. Some of the obtained solutions show that their existence is due only to the Kerr law nonlinearity presence. Graphical representations plotted have confirmed the hybrid and multi-form character of the obtained dispersive optical solitons. We believe that a good understanding of the hybrid dispersive optical solitons highlighted in the context of this work allows to grasp the physical description of systems whose dynamics are governed by nonlinear Schrödinger equation as studied in this work, allowing thereby a relevant improvement of complex problems encountered in particular in nonliear optaics and in optical fibers.

The similarity of interactions between (3+1)D spatiotemporal optical solitons in both the dispersive medium with cubic-quintic nonlinearity and the saturable medium

By making use of the split-step Fourier method, this paper numerically simulates dynamical behaviors, including repulsion, fusion, scattering and spiraling of colliding （3＋1）D spatiotemporal solitons in both the dispersive medium with cubic-quintic and the saturable medium. Careful comparison of the colliding behaviors in these two media is presented. Although the origin of the nonlinearities is different in these two media, the obtained results show that the dynamical behaviors are very similar. This presents additional evidence to support the supposition of universality of interactions between solitons.

Solitons for the cubic-quintic nonlinear Schrdinger equation with varying coefficients

In this paper,by means of similarity transfomations,we obtain explicit solutions to the cubic-quintic nonlinear Schr顜僤inger equation with varying coefficients,which involve four free functions of space.Four types of free functions are chosen to exhibit the corresponding nonlinear wave propagations.

Some Exact Solutions of Variable Coefficient Cubic-Quintic Nonlinear Schrdinger Equation with an External Potential

By constructing appropriate transformations and an extended elliptic sub-equation approach, we find some exact solutions of variable coefficient cubic-quintie nonlinear Schrodinger equation with an external potential, which include bell and kink profile solitary wave solutions, singular solutions, triangular periodic wave solutions and so on.

Stability Analysis of Damped Cubic-Quintic Duffing Oscillator

This paper presents a comprehensive stability analysis of the dynamics of the damped cubic-quintic Duffing oscillator. We employ the derivative expansion method to investigate the slightly damped cubic-quintic Duffing oscillator obtaining a uniformly valid solution. We obtain a uniformly valid solution of the un-damped cubic-quintic Duffing oscillator as a special case of our solution. A phase plane analysis of the damped cubic-quintic Duffing oscillator is undertaken showing some chaotic dynamics which sends a signal that the oscillator may be useful as model for prediction of earth- quake occurrence.

Evolution of finite energy Airy beams in cubic-quintic atomic vapor system

In a numerical investigation, we demonstrate the evolution of a one-dimensional and two-dimensional finite energy Airy beam in a A-type three-level atomic vapor with linear, cubic, and quintic susceptibilities considered simultaneously with the dressing effect. Quasi-solitons and soliton pairs are observed due to this competition mechanism. We find that the frequency detuning of the pump field and its power greatly affect the formation and evolution of generated solitons. In general, around the two- photon resonance point, and for low intensities of the pump field, it is less difficult to form solitons. This investigation enriches the study of the propagation properties of Airy beams and soliton generation in atomic vapor.

Stable high-dimensional solitons in nonlocal competing cubic-quintic nonlinear media

We find and stabilize high-dimensional dipole and quadrupole solitons in nonlocal competing cubic-quintic nonlinear media.By adjusting the propagation constant,cubic,and quintic nonlinear coefficients,the stable intervals for dipole and quadrupole solitons that are parallel to the x-axis and those after rotating 45°counterclockwise around the origin of coordinate are found.For the dipole solitons and those after rotation,their stability is controlled by the propagation constant,the coefficients of cubic and quintic nonlinearity.The stability of quadrupole solitons is controlled by the propagation constant and the coefficient of cubic nonlinearity,rather than the coefficient of quintic nonlinearity,though there is a small effect of the quintic nonlinear coefficient on the stability.Our proposal may provide a way to generate and stabilize some novel high-dimensional nonlinear modes in a nonlocal system.

Bright and dark optical solitons in the nonlinear Schrdinger equation with fourth-order dispersion and cubic-quintic nonlinearity

By the use of an auxiliary equation, we find bright and dark optical soliton and other soliton solutions for the higher-order nonlinear Schrodinger equation (NLSE) with fourth-order dispersion (FOD), cubic-quintic terms, self-steepening, and nonlinear dispersive terms. Moreover, we give the formation condition of the bright and dark solitons for this higher-order NLSE.

Bilinear Forms and Dark-Dark Solitons for the Coupled Cubic-Quintic Nonlinear Schrodinger Equations with Variable Coefficients in a Twin-Core Optical Fiber or Non-Kerr Medium

Twin-core optical fibers are applied in such fields as the optical sensing and optical communication,and propagation of the pulses,Gauss beams and laser beams in the non-Kerr media is reported.Studied in this paper are the coupled cubic-quintic nonlinear Schrodinger equations with variable coefficients,which describe the effects of quintic nonlinearity for the ultrashort optical pulse propagation in a twin-core optical fiber or non-Kerr medium.Based on the integrable conditions,bilinear forms are derived,and dark-dark soliton solutions can be constructed in terms of the Gramian via the Kadomtsev-Petviashvili hierarchy reduction.Propagation and interaction of the dark-dark solitons are presented and discussed through the graphic analysis.With different values of the delayed nonlinear response effect b(z),where z represents direction of the propagation,the linear-and parabolic-shaped one dark-dark soltions can be derived.Interactions between the parabolic-and periodic-shaped two dark-dark solitons are presented with b(z)as the linear and periodic functions,respectively.Directions of velocities of the two dark-dark solitons vary with z and the amplitudes of the solitons remain unchanged can be observed.Interactions between the two dark-dark solitons of different types are displayed,and we observe that the velocity of one soliton is zero and direction of the velocity of the other soliton vary with z.We find that those interactions are elastic.

Solution of nonlinear cubic-quintic Duffing oscillators using He’s Energy Balance Method

In this study, He＇s Energy Balance Method （EBM） was applied to solve strong nonlinear Duffing oscillators with cubic-quintic nonlinear restoring force. The complete EBM solution procedure of the cubic-quintic Duffing oscillator equation is presented. For illustration of effectiveness and convenience of the EBM, different cases of cubic-quintic Duffing oscillator with different parameters of α,β and y were compared with the exact solution. We found that the solutions were valid for small as well as large amplitudes of oscillation. The results show that the EBM is very convenient and precise, so it can be widely appli- cable in engineering and other sciences.

Nonautonomous Solitons in the(3+1)-Dimensional Inhomogeneous Cubic-Quintic Nonlinear Medium

We have constructed explicit nonautonomous soliton solutions of the generalized nonlinear Sehr6dinger equation in the （3＋ 1 ）-dimensionM inhomogeneous cubic-quintic nonlinear medium. The gain parameter has no effects on the motion of the soliton＇s phase or their velocities, and it affects just the evolution of their peaks. As two examples, we discuss the propagation of nonautonomous solitons in the periodic distributed amplification system and the exponential dispersion decreasing system. Results show that the presence of the chirp not only makes the intensity of solitons weaken more promptly, but also broadens their width.

On Solving the （2＋1）-Dimensional Nonlinear Cubic-Quintic Ginzburg-Landau Equation Using Five Different Techniques

In this article, we apply five different techniques, namely the （G//G）-expansion method, an auxiliary equation method, the modified simple equation method, the first integral method and the Riccati equation method for constructing many new exact solutions with parameters as well as the bright-dark, singular and other soliton solutions of the （2＋1）-dimensional nonlinear cubic-quintic Ginzburg-Landau equation. Comparing the solutions of this nonlinear equation together with each other are presented. Comparing our new results obtained in this article with the well-known results are given too.

Higher-Order Rogue Wave Pairs in the Coupled Cubic-Quintic Nonlinear Schr?dinger Equations

We study some novel patterns of rogue wave in the coupled cubic-quintic nonlinear Schr?dinger equations.Utilizing the generalized Darboux transformation, the higher-order rogue wave pairs of the coupled system are generated.Especially, the first-and second-order rogue wave pairs are discussed in detail. It demonstrates that two classical fundamental rogue waves can be emerged from the first-order case and four or six classical fundamental rogue waves from the second-order case. In the second-order rogue wave solution, the distribution structures can be in triangle,quadrilateral and ring shapes by fixing appropriate values of the free parameters. In contrast to single-component systems, there are always more abundant rogue wave structures in multi-component ones. It is shown that the two higher-order nonlinear coefficients ρ_1 and ρ_2 make some skews of the rogue waves.

Study of Exact Solutions to Cubic-Quintic Nonlinear Schrdinger Equation in Optical Soliton Communication

A systematic method which is based on the classical Lie group reduction is used to find the novel exact solution of the cubic-quintic nonlinear Schrdinger equation (CQNLS) with varying dispersion,nonlinearity,and gain or absorption.Algebraic solitary-wave as well as kink-type solutions in three kinds of optical fibers represented by coefficient varying CQNLS equations are studied in detail.Some new exact solutions of optical solitary wave with a simple analytic form in these models are presented.Appropriate solitary wave solutions are applied to discuss soliton propagation in optical fibres,and the amplification and compression of pulses in optical fibre amplifiers.

非Kerr光纤中亮孤子的稳定性与相互作用

非Kerr光纤中的亮孤子的演化可以用具有三次-五次竞争非线性项的非线性薛定谔方程来描述.为数值求解该方程的初值问题,本文将无界区域截断为有界区域,根据亮孤子在远场的渐近行为构造了合理的边界条件,从而将该初值问题转换为初边值问题.对这个初边值问题,本文分别提出了Crank-Nicolson有限差分(Crank-Nicolson Finite Difference, CNFD)格式和时间分裂有限差分(Time-Splitting Finite Difference, TSFD)格式.这两种格式在空间和时间维度上都具有二阶精度,其中CNFD格式是全隐格式,可以守恒离散能量和质量,TSFD是线性隐式格式,可以守恒离散质量.在以数值算例验证两种方法的计算效率后,本文用TSFD格式研究了非Kerr光纤中亮孤子的稳定性与相互作用.

基于多项式加减速的多头螺纹磨削算法研究

对多头螺纹进行磨削加工时,为了实现砂轮与切入点对齐,砂轮需要回到零点,并在零点等待一转信号和主轴转过偏转角度,而等待固定的信号会导致插补效率降低。针对这一问题,设计了一种基于混合非对称多项式加减速控制算法的多头螺纹快速分头算法。首先,分析了螺纹分头原理和砂轮切入方法,提取了切入点选择特征;然后,采用分区建立了插补时间规划模型,根据插补时间规划方法和砂轮切入点选择特征,建立了砂轮与每个切入点对齐的脉冲时间变化模型;之后,根据五次速度曲线加减速控制算法和三次速度曲线加减速控制算法的基本原理,设计了混合非对称多项式加减速控制算法模型,建立了参数控制模型及快退区目标速度预测模型;最后,采用MATLAB仿真的方法,验证了多头螺纹快速分头算法的正确性和有效性。研究结果表明:在工况1、工况2条件下(螺纹头数分别为20、25,其他条件相同),顺序切入和对称切入的加工效率分别提高了12.98%、0.67%,根据工况参数可以确定加工效率最高的砂轮切入方法;采用变加减速控制的方法,在快退区减速段可以实现±4 ms的容差控制目标,降低了砂轮与切入点对齐算法的容差压力;采用混合非对称多项式加减速控制算法,可以对多头螺纹快速分头插补和加加速度进行柔性控制,以提高螺纹分头的效率。