共查询到20条相似文献,搜索用时 623 毫秒
1.
We present new types of solitary wave solutions for the higher order nonlinear Schrodinger (HNLS) equation describing propagation of femtosecond light pulses in an optical fiber under certain parametric conditions. Unlike the reported solitary wave solutions of the HNLS equation, the novel ones can describe bright and dark solitary wave properties in the same expressions and their amplitude may approach nonzero when the time variable approaches infinity. In addition, such solutions cannot exist in the nonlinear Schrodinger equation. Furthermore, we investigate the stability of these solitary waves under some initial pertubations by employing the numerical simulation methods. 相似文献
2.
BAI Cheng-Lin ZHAO Hong ZHANG Li-Hua 《理论物理通讯》2006,46(8)
We propose two simple ans(a)tze that allow us to obtain different analytical solutions for two generalized versions of the nonlinear Schr(o)dinger equation, such as the averaged dispersive-managed fiber system equation and the extended nonlinear Schr(o)dinger equation which describe the femtosecond pulse propagation in monomode optical fiber.Among these solutions we can find solitary wave and periodic wave solutions representing the propagation of different waveforms in nonlinear media. 相似文献
3.
高非线性光纤产生自相似抛物线脉冲的特性研究 总被引:1,自引:0,他引:1
基于脉冲在光纤中传输所满足的非线性薛定谔方程,采用数值计算的方法对脉冲在高非线性光纤中演化成自相似抛物线脉冲的传输特性进行了研究。结果表明,脉冲在不同初始能量和啁啾参量的情况下,高非线性光纤产生自相似抛物线脉冲,且随着归一化长度的增大,脉冲的自相似指数从0.0796减小到0.0720。进一步的研究表明:啁啾高斯脉冲在光纤传输过程中,脉冲逐渐展宽,同时正啁啾越大,其自相似演化结果越差;参数N=8的正负啁啾脉冲分别演化成平顶自相似抛物线脉冲以及三角形脉冲。 相似文献
4.
Reccntly,thec]9ctrol13:lgrlcticProPcl'ticsinn0nIinearpcriodicstructurchavebcenexten-sively8tudiedW.ChenandD.L.A/[illsdeIn0nstratedthecxisting0fs0-cal1cdgaps0litoninnon1inearpcri0dicstructure[1J,thcsegapsolit0nsarespatiaIs0lit0ns.'Latterstudiesshowedthatthegaps0litonis0nlyakind0fspecialcflsc0fBraggs0Iiton\\'hichcanm0vewithanyve-locitybelox\'t[1egroLlpvcI0city[2,3j.Thcse.solit0nscxistinthcresonantcase,i-e-,thestr0ngcouplingbctxvcentt1cfor\\':lI'<1112odcanLIthcback\\'ardm0dc.Inthiscasc,the… 相似文献
5.
给出了描述连续波扰动下飞秒光脉冲在光纤系统中传输的微扰高阶非线性薛定谔方程,通过矩法和微扰理论分析了飞秒亮孤子与连续波相互作用的特性,并利用龙格-库塔积分和分步傅里叶方法进行了数值模拟.结果表明,连续波微扰对光纤孤子通讯系统是十分有害的,在实际通讯过程中应当尽量避免连续波的渗入. 相似文献
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7.
《Physics letters. A》2020,384(31):126810
In this paper, we consider the new model of nonlinear contacting media based on nonlinear Schrodinger equation with point potential and term, which is depended stepwise on field amplitude. Such a model theoretically describes a change in properties of the boundary regions along the interface between a Kerr-type crystal with cubic nonlinearity and a nonlinear medium characterized by abruptly change in dielectric constant depending on field amplitude. The short-range local interaction between wave and interface is taken into account by point potential in nonlinear Schrodinger equation. We obtain two new types of localized states characterized by composite structure consisting of three parts of the field distributions. We find exact and approximate solutions of dispersion equations. We described new properties of the spectrum of localized states arising as a result of the interaction of the wave with the interface and the presence of threshold field of the switching between the medium constants. All results are obtained in an analytical form. The proposed theory can be used to describe the propagation features of intense light beams localized along media interfaces in nonlinear optics, and to describe Bose-Einstein condensates with cubic nonlinearity. 相似文献
8.
We show that the nonlinear equation governing wave propagation in a loss fibre system considered byNakkeeran in J. Phys. A34 (2001) 5111 can be brought into the standard nonlinear Schrodinger equation by a simpletransformation. 相似文献
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10.
Nonlinear Schrodinger equation (NLSE) is now one of the prominent of modern physics, mathematics and chemistry. Over these fields, the NLSE is also applied in new emerging fields such as quantum information and econophysics. In this paper we investigate for new exact solutions of higher order nonlinear Schrodinger’s equation. This method allows to carry out the solution process of nonlinear wave equations more thoroughly and conveniently by computer algebra systems such as the Maple and Mathematica. In addition to providing a different way of solving the Schrodinger equation for such systems, the simplicity of the algorithm renders it a great pedagogical value. 相似文献
11.
By using the generally projective Riccati equation method, more new exact travelling wave solutions to extended
nonlinear Schrödinger equation (NLSE), which describes the
femtosecond pulse propagation in monomode optical fiber,
are found, which include bright soliton solution, dark soliton
solution, new solitary waves, periodic solutions, and rational
solutions. The finding of abundant solution structures for
extended NLSE helps to study the movement rule of femtosecond
pulse propagation in monomode optical fiber. 相似文献
12.
We present two methods that allow for the efficient numerical propagation of continuum wave packets to large times. Time-dependent solutions of the Schrodinger equation that include continuum components are numerically challenging to solve because the wave packet travels, spreads, and acquires a spatial phase gradient. The methods we propose account for these kinematic effects analytically in general and numerically tractable schemes. 相似文献
13.
本文基于变系数的非线性薛定谔方程,数值地讨论高峰值脉冲在色散渐减光纤中的激发和传输。首先,基于变系数非线性薛定谔方程的Peregrine孤子解,解析和数值地讨论精确的Peregrine孤子在色散渐减光纤中的传输特性。其次,通过输入不同的平面波背景上的局域脉冲,研究高峰值脉冲在非线性色散渐减光纤中的激发和传输。结果显示Peregrine孤子在色散渐减光纤中传输时,会产生一个空间和时间都局域化的高峰值单脉冲,并且当啁啾为负时,脉冲的幅值增加,脉宽被压缩。若光纤系统存在增益,脉冲的幅值也会增加。由于非线性光纤中的调制不稳定性过程,不同平面波背景上的小局部扰动都可激发出高峰值脉冲,除了峰值和宽度略有不同外,激发脉冲的形状几乎相同。 相似文献
14.
双折射色散阶跃光纤中拉曼效应和参量放大增益谱 总被引:1,自引:1,他引:0
在拉曼效应和参量放大共同作用下,当激光脉冲在双折射光纤中传输时,根据所遵循的耦合模方程,通过引入平行拉曼增益的洛伦兹模型,导出了当输入泵浦波偏振方向同双折射轴成45°角时,在双折射色散阶跃光纤中拉曼效应和参量放大共同作用所导致的增益,讨论并分析了在不同色散区增益谱随相关参量的变化。结果表明:由于拉曼效应、参量放大、双折射和色散的相互作用,导致增益谱的斯托克斯波与反斯托克斯波彼此不对称;在反常色散区,产生的增益以反斯托克斯波为主,在正常色散区则以斯托克斯波为主;当表征距离的级数m发生变化时,增益谱也随之发生变化,可以利用色散阶跃光纤在适当的级数m位置提取T频率脉冲。 相似文献
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16.
Pulse Propagation with Self-Phase Modulation in Nonlinear Chiral Fiber and Its Applications 下载免费PDF全文
《中国物理快报》2016,(9)
From Maxwell's equations and Post's formalism,a generalized chiral nonlinear Schrodinger equation(CNLSE) is obtained for the nonlinear chiral fiber.This equation governs light transmission through a dispersive nonlinear chiral fiber with joint action of chirality in linear and nonlinear ways.The generalized CNLSE shows a modulation of chirality to the effect of attenuation and nonlinearity compared with the case for a conventional fiber.Simulations based on the split-step beam propagation method reveal the role of nonlinearity with cooperation to chirality playing in the pulse evolution.By adjusting its strength the role of chirality in forming solitons is demonstrated for a given circularly polarized component.The application of nonlinear optical rotation is also discussed in an all-optical switch. 相似文献
17.
M. Idrish Miah 《Optik》2011,122(1):55-57
We study the nonlinear wave propagation in an inhomogeneous optical fiber core in the normal dispersive regime. In order to include the inhomogeneous physical effects, the nonlinear Schrödinger equation (NLSE), which governs the solitary pulse propagation in optical fiber, is modified by adding terms for phase modulation and power gain or loss. The modified NLSEs are bilinearized and exact dark soliton solutions are obtained. The results are discussed. 相似文献
18.
GE Jian-Ya WANG Rui-Min DAI Chao-Qing ZHANG Jie-Fang 《理论物理通讯》2006,46(4):656-662
In this paper, by means of the variable-coefficient mapping method based on elliptical equation, we obtain explicit solutions of nonlinear Schrodinger equation with variable-coefficient. These solutions include Jacobian elliptic function solutions, solitary wave solutions, soliton-like solutions, and trigonometric function solutions, among which some are found for the first time. Six figures are given to illustrate some features of these solutions. The method can be applied to other nonlinear evolution equations in mathematical physics. 相似文献
19.
Solutions of Two Kinds of Non-Isospectral Generalized Nonlinear Schrodinger Equation Related to Bose-Einstein Condensates 下载免费PDF全文
Two non-isospectral generalized nonlinear Schrodinger (ONLS) equations, which are two important models of nonlinear excitations of matter waves in Bose-Einstein condensates, are studied. Two novel transformations are constructed such that these two GNLS equations are transformed to the well-known nonlinear Schr6dinger (NLS) equation, which is an isospectral equation. Therefore, once one solution of the NLS equation is provided, we can immediately obtain one solution for two ONLS equations by these transformations. Thus it is unnecessary to solve these two non-isospectral GNLS equations directly. Soliton solutions and periodic solutions are obtained for them by two transformations from the corresponding solutions of the NLS equation, which are generated by Darboux transformation. 相似文献
20.
This article studies the performance of analytical, semi-analytical and numerical scheme on the complex nonlinear Schr¨odinger(NLS) equation. The generalized auxiliary equation method is surveyed to get the explicit wave solutions that are used to examine the semi-analytical and numerical solutions that are obtained by the Adomian decomposition method, and B-spline schemes(cubic, quantic, and septic). The complex NLS equation relates to many physical phenomena in different branches of science like a quantum state, fiber optics, and water waves. It describes the evolution of slowly varying packets of quasi-monochromatic waves, wave propagation, and the envelope of modulated wave groups, respectively. Moreover, it relates to Bose-Einstein condensates which is a state of matter of a dilute gas of bosons cooled to temperatures very close to absolute zero. Some of the obtained solutions are studied under specific conditions on the parameters to constitute and study the dynamical behavior of this model in two and three-dimensional. 相似文献