共查询到19条相似文献,搜索用时 114 毫秒
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通过连续波背景上的小幅近似,给出了光纤中增益色散及双光子吸收所支持的小幅暗孤波解,讨论了它们在参数空间中不同区域的演化特征,结果表明:在一些区域存在稳定的小振幅暗孤波,但在另一些区域,这种孤波是不稳定的。 相似文献
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以描述负折射介质中超短脉冲传输的归一化非线性薛定谔方程为模型,采用对称分步傅里叶算法研究了负折射介质中亮、暗孤波间的相互作用.数值模拟发现:当孤波的初始频移为零时,亮孤波间的相互作用与常规介质中类似;当孤波的初始频移不为零时,其传输速度和相互作用明显受三阶色散和自陡峭效应的影响,主要表现为相互排斥.而负折射介质中暗孤波间的相互作用与常规介质中的相互作用类似,无论暗孤波是否存在初始频移,暗孤波间的相互作用在三阶色散和自陡峭的影响下都表现为相互排斥.结果表明,通过调节三阶色散和自陡峭系数可以在一定程度上抑制负折射介质中亮、暗孤波间的相互作用.该研究结果为负折射介质在未来高速通信中的应用提供了理论依据. 相似文献
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以描述负折射介质中超短脉冲传输的归一化非线性薛定谔方程为模型,采用对称分步傅里叶算法研究了负折射介质中亮、暗孤波间的相互作用.数值模拟发现:当孤波的初始频移为零时,亮孤波间的相互作用与常规介质中类似;当孤波的初始频移不为零时,其传输速度和相互作用明显受三阶色散和自陡峭效应的影响,主要表现为相互排斥.而负折射介质中暗孤波间的相互作用与常规介质中的相互作用类似,无论暗孤波是否存在初始频移,暗孤波间的相互作用在三阶色散和自陡峭的影响下都表现为相互排斥.结果表明,通过调节三阶色散和自陡峭系数可以在一定程度上抑制负折射介质中亮、暗孤波间的相互作用.该研究结果为负折射介质在未来高速通信中的应用提供了理论依据. 相似文献
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在光纤零群速色散区传输的光孤子波 总被引:1,自引:0,他引:1
通过对超短光脉冲在单模光纤中传输方程的分析研究,给出了在零群速色散传输方程的亮,反波解。结果表明,超短光脉中在光纤的零群群速色散仍能以亮,暗孤波的形式传输,且不存在孤子自频移现象。 相似文献
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利用扰动法,由包括耗散和地形的准地转位涡度方程导出了强迫mKdV-Burgers方程,求得了小耗散情形下mKdV-Burgers方程的近似分析解,分析了mKdV孤波质量和能量的时间演变特性。对给定的局地地形,利用拟谱法对强迫mKdV-Burgers方程进行了数值求解。结果显示,小耗散的存在使弧波的振幅和移速随时间缓慢地减小,孤波宽度则随时间缓慢增大;在耗散和地形强迫的非线性系统中,在孤波与地形的相互作用中,耗散的存在使孤波在强迫区附近振荡传播,这有利于大振幅扰动的形成。 相似文献
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Small-amplitudesolitonsinnonlinear-saturationglassfibersSmall-amplitudesolitonsinnonlinear-saturationglassfibers¥YUZhongyuan;... 相似文献
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利用F-函数扩展法求解超介质中的超短脉冲传输方程, 探讨了超介质中的反常自陡效应和特有的二阶非线性色散效应所导致的新的孤子现象和规律. 结果表明, 正折射区的二阶非线性色散效应可以代替线性色散效应形成亮孤子; 正、负折射区的反常自陡效应由于其符号可改变, 从而可在特定条件下分别在反常色散和正常色散区形成有别于常规介质的亮、暗孤子; 反常自陡效应的符号或者反常自陡效应和三阶线性色散效应的相互比较关系能够控制亮、暗孤子中心的漂移方向.
关键词:
孤子
超介质
F-函数扩展法 相似文献
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THE TRANSMISSION PROPERTIES OF SOLITON ON THE CW BACKGROUND NEAR THE ZERO-DISPERSION WAVELENGTH 下载免费PDF全文
By using the perturhation theory and small-amplitude approximation with the self-induced Raman effect and the loss as well as gain of the fiber taken into account, the transmission properties of solitons in the nomal dispersion region near the zero-group-dispersion wavelength are analytically investigated in this paper. The result shows that not only the small-amplitude dark soliton but also the small-amplitude bright soliton may exist in the normal dispersion region near the zero-group-dispersion point. Their stabilities depend on the propagating direction and the region in which they are situated in the parameter-space. The conversion between bright and dark solitons may be realized by controlling the relative intensities of gain and loss along the fiber. This may be applied to the logic or arithmetic devices in the integrated optical circuit. 相似文献
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Morandotti R Eisenberg HS Silberberg Y Sorel M Aitchison JS 《Physical review letters》2001,86(15):3296-3299
We show that two regimes of diffraction exist in arrays of waveguides, depending upon the input conditions. At higher powers, normal diffraction leads to self-focusing and to the formation of bright solitons through the nonlinear Kerr effect. By slightly changing the input conditions, light experiences anomalous diffraction and is nonlinearly defocused. For the first time, self-focusing and self-defocusing have been achieved for the same medium, structure, and wavelength. 相似文献
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The ultimate theme of this study is to develop dipole and combo optical solitons in birefringent fibers (BF) along with the effect of four-wave mixing (4WM). Two types of rough mediums are used which are Kerr law and parabolic law. Ansatz method of Choudhuri is applied to obtain dark in the bright (dipole) soliton solutions providing bright background for the propagation of optical dark pulse. Ansatz method of Li is applied to obtain combo soliton solutions providing bright solitary wave and dark solitary wave solutions. These results also exist to hold in non-Kerr media with higher order dispersion. 相似文献
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Eiermann B Anker T Albiez M Taglieber M Treutlein P Marzlin KP Oberthaler MK 《Physical review letters》2004,92(23):230401
We report on the first experimental observation of bright matter wave solitons for 87Rb atoms with repulsive atom-atom interaction. This counterintuitive situation arises inside a weak periodic potential, where anomalous dispersion can be realized at the Brillouin zone boundary. If the coherent atomic wave packet is prepared at the corresponding band edge, a bright soliton is formed inside the gap. The strength of our system is the precise control of preparation and real time manipulation, allowing the systematic investigation of gap solitons. 相似文献
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Dispersion-managed solitons at normal average dispersion 总被引:2,自引:0,他引:2
We find that in a dispersion-managed fiber, in which the strength of the dispersion management is above some threshold, solitons can exist with normal average dispersion. When the normal average dispersion is below some limiting value there exist two soliton solutions with the same pulse duration and different pulse energies. When the normal average dispersion is above this limiting value, no soliton exists. Both higher-energy and lower-energy solitons are dynamically stable in the parameter range that we considered. 相似文献
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结合均匀光子晶格的衍射关系和晶格中正负缺陷的布里渊区谱特性,探讨了光诱导二维光子晶格中线性缺陷模式的形成条件,对布里渊区中各点的缺陷模式进行了模拟分析,并得到了光子带隙结构中“嵌入点”X1点的正、负缺陷模式.结果表明:对于二维缺陷,只有当衍射关系曲面中沿两个正交的横向波矢方向同时为正常(反常)衍射的区域才能存在正(负)缺陷模式;而对于一维缺陷,只要在一个横向波矢方向上存在正常(反常)衍射的区域就可以支持正(负)缺陷模式,因此在某些特殊点处,正和负的缺陷模式可以同时存在.X1点正缺陷模式的存在预示着自聚焦非线性同样可以支持带内孤子.研究结果有助于对光子晶格中晶格孤子(特别是带内孤子)的理解和进一步研究.
关键词:
光诱导光子晶格
光子带隙
线性缺陷态 相似文献
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Nonautonomous bright solitons and soliton collisions in a nonlinear medium with an external potential 下载免费PDF全文
We present exact bright multi-soliton solutions of a generalized nonautonomous nonlinear Schrdinger equation with time-and space-dependent distributed coefficients and an external potential which describes a pulse propagating in nonlinear media when its transverse and longitudinal directions are nonuniformly distributed.Such solutions exist in certain constraint conditions on the coefficients depicting dispersion,nonlinearity,and gain(loss).Various shapes of bright solitons and interesting interactions between two solitons are observed.Physical applications of interest to the field and stability of the solitons are discussed. 相似文献