共查询到20条相似文献,搜索用时 46 毫秒
1.
Didier Belobo Belobo Germain Hubert Ben-Bolie Thierry Blanchard Ekogo Timoléon Crépin Kofané 《International Journal of Theoretical Physics》2013,52(5):1415-1430
We investigate the modulational instability of matter-wave condensates in a modified Gross-Pitaevskii equation which takes into account effects of the three-body interaction. This three-body interaction consists of a quintic term and an additional one representing the delayed nonlinear response of condensates which are trapped both in an attractive and a repulsive harmonic potentials. Our theoretical study uses a modified lens-type transformation and we obtain a modulational instability criterion, and an explicit growth rate. We show that the presence of the three-body interaction destabilizes the condensate, and enhances the appearance of instability in the condensate. Numerical experiments agree well with analytical predictions. Furthermore, our numerical simulations show that the three-body interaction modifies the symmetry of the trail of soliton chains created. The expulsive potential enhances the instability, while the attractive potential appears to soften the instability. 相似文献
2.
El-Ganainy R Christodoulides DN Musslimani ZH Rotschild C Segev M 《Optics letters》2007,32(21):3185-3187
We investigate the modulation instability of plane waves and the transverse instabilities of soliton stripe beams propagating in nonlinear nanosuspensions. We show that in these systems the process of modulational instability depends on the input beam conditions. On the other hand, the transverse instability of soliton stripes can exhibit new features as a result of 1D collapse caused by the exponential nonlinearity. 相似文献
3.
Anastassiou C Soljacic M Segev M Eugenieva ED Christodoulides DN Kip D Musslimani ZH Torres JP 《Physical review letters》2000,85(23):4888-4891
We show analytically, numerically, and experimentally that a transversely stable one-dimensional [(1+1)D] bright Kerr soliton can exist in a 3D bulk medium. The transverse instability of the soliton is completely eliminated if it is made sufficiently incoherent along the transverse dimension. We derive a criterion for the threshold of transverse instability that links the nonlinearity to the largest transverse correlation distance for which the 1D soliton is stable. 相似文献
4.
Modulational instability of incoherently coupled beams in azobenzene-containing polymer with photoisomerization nonlinearity
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The modulational instability of two incoherently coupled beams in
azobenzene-containing polymer with photoisomerization nonlinearity
is investigated analytically and numerically. Our results show that
as a precursor to spatial optical soliton formation, modulational
instability can be adjusted and controlled by the wavelength
combinations of the signal and background beams. We also discuss the
dependences of strength of modulational instability on intensities
of two signal beams and background beam. These findings make it
possible to predict the formation of incoherently coupled soliton
pairs in azobenzene-containing polymer. 相似文献
5.
We report on the experimental observation of induced solitons in a passively mode-locked fiber ring laser with a birefringence cavity. Owing to the cross coupling between the two orthogonal polarization components of the laser, it was found that if a soliton was formed along one cavity polarization axis, a weak soliton was also induced along the orthogonal polarization axis, and depending on the net cavity birefringence, the induced soliton could have either the same or different center wavelengths to that of the inducing soliton. Moreover, the induced soliton always had the same group velocity as that of the inducing soliton. They formed a vector soliton in the cavity. Numerical simulations confirmed the experimental observations. 相似文献
6.
The intrinsic evolution of a high-order soliton described by the nonlinear Schr?dinger equation is initiated by a self-four-wave mixing effect (or modulational instability) and recurs neatly every soliton period. We show that when there is noise such as amplified spontaneous emission, however, a high-order soliton evolves randomly and independently and is distorted because the evolution is initiated by noise. Thus the time and the frequency coherence of a soliton pulse train are both greatly degraded. 相似文献
7.
We show numerically that when a soliton circulating in the laser cavity experiences dynamical bifurcations, extra sets of sidebands appear in the soliton spectrum. The new sidebands have clearly different characteristics to those of the conventional soliton sidebands, indicating that there exists a new mechanism of sideband generation in the lasers. 相似文献
8.
Cambournac C Sylvestre T Maillotte H Vanderlinden B Kockaert P Emplit P Haelterman M 《Physical review letters》2002,89(8):083901
We show experimentally that the two-component multimode spatial optical vector soliton, i.e., a two-hump self-guided laser beam, exhibits in Kerr media a sharp space-inversion symmetry-breaking instability. The experiment is performed in a CS2 planar waveguide using the orthogonal circular polarization states of light as the two components of the vector soliton. 相似文献
9.
10.
Z. C. Luo W. C. Xu C. X. Song A. P. Luo W. C. Chen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(3):693-697
Modulation instability with subsideband generation induced by periodic power variation in soliton fiber ring lasers is reported.
We found that different wavelength shifts of subsideband generation are related to different periodic power variation. The
period of power variation and wavelength shifts of subsideband can be changed by altering the linear cavity phase delay. It
is also found that the periodic power variation is caused by the interaction between the nonuniform polarization state of
the circulating light and the polarizer in the laser cavity. 相似文献
11.
The dynamical behavior of various physical and biological systems under the influence of delayed feedback or coupling can be modeled by including terms with delayed arguments in the equations of motion. In particular, the case of long delay may lead to complicated and high-dimensional dynamics. We investigate the effects of delay in systems that display an oscillatory instability (Hopf bifurcation) in the absence of delay. We show by analytical and numerical methods that the dynamical scenario includes the coexistence of multiple stable periodic solutions and can be described in terms of the Eckhaus instability, which is well known in the context of spatially extended systems. 相似文献
12.
Krolikowski W Ostrovskaya EA Weilnau C Geisser M McCarthy G Kivshar YS Denz C Luther-Davies B 《Physical review letters》2000,85(7):1424-1427
We report on the first experimental observation of a novel type of optical vector soliton, a dipole-mode soliton, recently predicted theoretically. We show that these vector solitons can be generated in a photorefractive medium employing two different processes: a phase imprinting, and a symmetry-breaking instability of a vortex-mode vector soliton. The experimental results display remarkable agreement with the theory, and confirm the robust nature of these radially asymmetric two-component solitary waves. 相似文献
13.
We report on the experimental and numerical studies of the chaotic dynamics of a soliton fiber ring laser passively mode-locked by using the nonlinear polarization rotation (NPR) technique. Period-doubling route to chaos on the soliton repetition rate of either the single pulse soliton or the bound solitons of the laser was experimentally observed. Based on a coupled complex Ginzburg-Landau equation model and also taking into account the laser cavity effect, we further show numerically that the period-doubling bifurcations and route to chaos are intrinsic properties of the laser, whose appearance is independent of the details of the laser cavity design and the laser soliton operation. Property of the solitons under the dynamical bifurcations is also numerically investigated. 相似文献
14.
应用一维相对论电磁粒子模拟程序,研究了线性极化强激光入射到无碰撞密度均匀的次临界密度等离子体中所引起的受激陷俘电子声波散射不稳定性过程.不稳定性的早期行为与是否考虑离子动力学效应无关.当考虑离子动力学效应之后会激发一个随时间增长的离子声波,并且最终由于大振幅电磁孤立子的产生而中断.由于电磁孤立子内的静电场与电磁场所产生的离子加速与俘获效应,导致一个离子涡旋在离子相空间中形成;当电磁孤立子向后加速过程中,若干个离子涡旋结构随之形成.研究发现,离子涡旋结构同样存在于密度不均匀的次临界密度等离子体中.从拓扑的观
关键词:
粒子模拟
受激陷俘电子声波散射
电磁孤立子
离子涡旋 相似文献
15.
提出一种将延时光电反馈引入两段式双稳半导体激光器(TBLD)的吸收区,从而达到控制其双稳及自脉动特性的方案.利用速率方程模型,分析了反馈增益及延迟时间对TBLD双稳及不稳定特性的控制作用.数值模拟的结果表明:TBLD的稳定区域随延迟时间呈周期性变化;双稳区域随延迟时间的增大而变窄;在一定的取值范围内,增大延迟时间有利于增强双稳的稳定性;负反馈更容易出现不稳定性.
关键词:
两段式双稳半导体激光器
动态双稳
自脉动
延时光电反馈 相似文献
16.
G. Huyet P. A. Porta S. P. Hegarty J. G. McInerney F. Holland 《Optics Communications》2000,180(4-6):339-344
We derive a low-dimensional dynamical system to describe a semiconductor laser with optical feedback. This model captures many features from the original time delayed dynamical system and explains the origin of the low-frequency instability observed in the time-delayed equation. 相似文献
17.
We show that oscillating dark solitons exist on a stable continuous plane-wave background in a cavity with a saturable defocusing nonlinearity. These oscillations can be attributed to a linear internal mode of the soliton with a complex eigenvalue emerging above a definite input field intensity. Using a simple analytical model, we find that the self-oscillations appear as a consequence of an interaction between the center of the soliton and the surrounding ring. 相似文献
18.
We show, by performing linear stability analysis and direct numerical simulations, that dark-soliton transverse instability is significantly reduced in Kerr media by strong coupling to a bright soliton. High instability suppression can be achieved by use of large-amplitude bright solitons. 相似文献
19.
We show numerically the existence of vibrating soliton pairs that are consistent with observations performed with a passively mode-locked fiber laser. These vibrating pairs are new types of multisoliton complexes that exist in the vicinity of the phase-locked soliton pairs discovered a few years ago [Opt. Lett.27, 966 (2002)]. The pairs are found numerically with a laser propagation model that includes nonlinear dissipation and cavity periodicity, and they can appear following a Hopf-type bifurcation when a cavity parameter is tuned. 相似文献
20.
M. Bache F. Prati G. Tissoni R. Kheradmand L.A. Lugiato I. Protsenko M. Brambilla 《Applied physics. B, Lasers and optics》2005,81(7):913-920
We study theoretically a broad-area vertical cavity surface emitting laser (VCSEL) with a saturable absorber. We show numerically
the presence of cavity solitons in the system: they exist as solitary structures formed through a modulationally unstable
homogeneous lasing state that coexists with a background with zero intensity. Such a peculiar scenario endows the solitons
with unique properties compared to cavity solitons in most previously studied optical systems. In particular, these solitons
do not as such rely on a proper phase of the addressing pulses to be either created or deleted. We show that exciting and
deleting the solitons depend crucially on whether a threshold in the soliton peak has been reached. 相似文献