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Min Li Bo Tian Wen-Jun Liu Yan Jiang Kun Sun 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,59(2):279-289
Coupled modified nonlinear Schr?dinger (CMNLS) equations
describe the pulse propagation in the picosecond or femtosecond
regime of the birefringent optical fibers. A new type of the Lax
pair and another hierarchy of the infinitely many conservation laws
are derived based on the Wadati-Konno-Ichikawa system. By means of
the Hirota method, soliton solutions in the normal dispersion regime
are obtained. Parametric regions for the existence of dark and
anti-dark vector soliton solutions are given. Asymptotic analysis
shows that the collision between two solitons (two anti-dark
solitons, two dark solitons, or dark and anti-dark solitons) in each
polarization direction is elastic. Moreover, there is no energy
transfer between two polarization components of each vector soliton,
whether dark or anti-dark vector soliton. In addition, dark and
anti-dark solitons can coexist on the same background seen from the
collision between the dark and anti-dark solitons in one
polarization direction. Our graphical analysis shows that the
parameters in the CMNLS equations not only determine the regions for
the existence of dark and anti-dark soliton solutions but also
control the phase and direction of the propagation of the solitons.
Finally, through the linear stability analysis, the modulational
instability condition is given. 相似文献
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We investigate theoretically the temperature effects on the evolution and stability of a separate holographic–Hamiltonian dark–dark or bright–dark soliton pair formed in an unbiased serial photorefractive crystal circuit. Our numerical results show that, for a stable dark–dark or bright–dark soliton pair originally formed in a crystal circuit at given temperatures, when the crystal in which formed a Hamiltonian dark soliton changes, the holographic dark or bright soliton supported by the other crystal tends to evolve into another stable soliton or experiences larger cycles of compression or breaks up into beam filaments or exhibit a common decaying process. The holographic dark soliton is more sensitive to the temperature change than the holographic bright one. 相似文献
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We respectively investigate breakup and switching of the Manakov-typed bound vector solitons (BVSs) induced by two types of stochastic perturbations: the homogenous and nonhomogenous. Symmetry-recovering is discovered for the asymmetrical homogenous case, while soliton switching is found to relate with the perturbation amplitude and soliton coherence. Simulations show that soliton switching in the circularly-polarized light system is much weaker than that in the Manakov and linearly-polarized systems. In addition, the homogenous perturbations can enhance the soliton switching in both of the Manakov and non-integrable (linearly- and circularly-polarized) systems. Our results might be helpful in interpreting dynamics of the BVSs with stochastic noises in nonlinear optics or with stochastic quantum fluctuations in Bose–Einstein condensates. 相似文献
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We show that incoherently coupled soliton pairs can
exist in nonlocal Kerr-type nonlinear media. Such
solitons can propagate in bright--bright, dark--dark, and gray--gray
configurations. When the nonlocal nonlinearity is absent, these
bright--bright and dark--dark soliton pairs are those observed
previously in local Kerr-type nonlinear media. Our analysis
indicates that for a self-focusing nonlinearity the intensity full
width half maximum (FWHM) of the bright--bright pair components
increases with the degree of nonlocality of the nonlinear response,
whereas for a self-defocusing nonlinearity the intensity FWHM of the
dark--dark and gray--gray pair components decreases with the
increase in the degree of nonlocality of the nonlinear response. The
stability of these soliton pairs has been investigated numerically
and it has been found that they are stable. 相似文献
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We show that the dark soliton of the Gross-Pitaevskii equation (GPE) that describes the Bose-Einstein condensate (BEC) density of a system of weakly repulsive bosons, also describes that of a system of strongly repulsive hard core bosons at half filling. As a consequence of this, the GPE soliton gets related to the magnetic soliton in an easy-plane ferromagnet, where it describes the square of the in-plane magnetization of the system. These relationships are shown to be useful in understanding various characteristics of solitons in these distinct many-body systems. 相似文献
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We investigate theoretically the dark soliton crystal temperature effect on the deflection of the bright one in a bright–dark soliton pair which is formed in a serial non-photovoltaic photorefractive crystal circuit. Our numerical results show that the spatial shift of the bright soliton changes with the temperature of the dark one crystal and varying the temperature of the dark soliton crystal can influence the deflection strongly. The temperature dependence of the deflection process is further studied by perturbation technique and the results are found to be good agreement with that obtained by numerical method. Relevant examples are provided. 相似文献
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Ram Krishna Sarkar 《Optik》2010,121(4):339-346
In this paper, using parabolic equation approach, coupled propagation of two coaxially co-propagating and mutually incoherent bright cylindrical beams in saturable nonlinear medium has been investigated. Considering the coupling coefficient equal to unity (κ=1), a detailed account of formation of spatial soliton pair (i.e. both beams are stationary trapped) and spatial breather pair (i.e. width of each beam oscillates with the propagation distance) has been provided and existence of spatially trapped breather pair (i.e. average width of each breather of the pair does not change with the propagation distance) has been shown. Conditions of formation of trapped spatial breather pair and their existence line has also been revealed for arbitrary beam width ratio of the beams. It is revealed that spatial soliton pairs are just a special case of trapped breather pair. The regions (conditions) of mutual-focusing and mutual-defocusing of spatial soliton pair/breather pair have also been identified. Lastly, the law of trapped breather pair formation is proposed. 相似文献
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Effects of temperature on the stability of separatescreening bright--dark spatial soliton pair 下载免费PDF全文
We investigate theoretically the temperature effects on the evolution and stability
of a separate screening bright--dark soliton pair formed in a serial
non-photovoltaic photorefractive crystal circuit. Our numerical results show that,
for a stable bright--dark soliton pair originally formed in a crystal circuit at
given temperatures, when one crystal temperature changes, the soliton supported by
the other crystal will evolve into another stable soliton if the temperature change
is quite small, whereas it will become unstable and experience larger cycles of
compression or break up into beam filaments if the temperature difference is big
enough. The dark soliton is more sensitive to the temperature change than the bright
one. 相似文献
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We investigated the soliton solution for N coupled nonlinear Schrödinger (CNLS) equations. These equations are coupled due to the cross-phase-modulation (CPM). Lax pair of this system is obtained via the Ablowitz–Kaup–Newell–Segur (AKNS) scheme and the corresponding Darboux transformation is constructed to derive the soliton solution. One and two soliton solutions are generated. Using two soliton solutions of 3 CNLS equation, nonlinear tunneling of soliton for both with and without exponential background has been discussed. Finally cascade compression of optical soliton through multi-nonlinear barrier has been discussed. The obtained results may have promising applications in all-optical devices based on optical solitons, study of soliton propagation in birefringence fiber systems and optical soliton with distributed dispersion and nonlinearity management. 相似文献
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《中国物理快报》2020,(3)
We report the quantized superfluid vortex filaments induced by the axial flow effect, which exhibit intriguing loop structures on helical vortexes. Such new vortex filaments correspond to a series of soliton excitations including the multipeak soliton, W-shaped soliton, and anti-dark soliton, which have no analogue when the axial flow effect is absent. In particular, we show that the vortex filaments induced by the multipeak soliton and W-shaped soliton arise from the dual action of bending and twisting of the vortex, while the vortex filament induced by the anti-dark soliton is caused only by the bending action, which is consistent with the case of the standard bright soliton. These results will deepen our understanding of breather-induced vortex filaments and will be helpful for controllable ring-like excitations on vortices. 相似文献
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For the propagation of the ultrashort pulses in an inhomogeneousmulti-component nonlinear medium, a system of coupled equations isanalytically studied in this paper. Painlevé analysis shows thatthis system admits the Painlevé property under some constraints.By means of the Ablowitz-Kaup-Newell-Segur procedure, the Lax pairof this system is derived, and the Darboux transformation (DT) isconstructed with the help of the obtained Lax pair. With symboliccomputation, the soliton solutions are obtained by virtue of the DTalgorithm. Figures are plotted to illustrate the dynamical featuresof the soliton solutions. Characteristics of the solitonspropagating in an inhomogeneous multi-component nonlinear medium arediscussed: (i) Propagation of one soliton and two-peak soliton; (ii) Elastic interactions of the parabolic two solitons; (iii) Overlapphenomenon between two solitons; (iv) Collision of two head-onsolitons and two head-on two-peak solitons; (v) Two different typesof interactions of the three solitons; (vi) Decomposition phenomenonof one soliton into two solitons. The results might be useful in thestudy on the ultrashort-pulse propagation in the inhomogeneousmulti-component nonlinear media. 相似文献
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Amarendra K. Sarma 《Optics & Laser Technology》2009,41(3):247-217
Dark soliton switching in a nonlinear directional coupler in the presence of intermodal dispersion, cross-phase modulation (CPM), third-order dispersion, Raman effect, and self-steepening effect is reported for the first time. It is shown that, with the exception of CPM, all of the other perturbative effects have almost no effect on the switching characteristics of the dark soliton switch, which is an improvement over the corresponding bright soliton switch. Although the CPM increases the critical power of dark soliton switching, the soliton pulse remains stable inside the coupler during its propagation. 相似文献
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Separate holographic screening soliton pairs in a biased series photorefractive crystal circuit 下载免费PDF全文
Holographic dark (bright) screening solitons are predicted
in one dimension for a series circuit consisting of two
photorefractive crystals connected electronically by electrode leads
in a chain with a voltage source. Each crystal can support a
holographic screening soliton. The two solitons are known
collectively as a separate holographic screening soliton pair with
three types: bright--bright, bright--dark and dark--dark. The
numerical results show that the two solitons in a soliton pair can
affect each other through a light-induced current and their coupling
can affect their spatial profiles under the limit in which the
optical wave has a spatial extent much less than the width of the
crystal. 相似文献
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《Physics letters. A》2014,378(18-19):1228-1232
Exact unified rational solutions describing a family of Peregrine solitons as well as related algebraic soliton pairs in either self-focusing or self-defocusing Kerr media are presented, with distinct defining regimes and an explicit relationship for those of opposite nonlinearity. The active role of the space–time correction effect that plays in these soliton species is highlighted, leading to unique dynamics such as the persistence of Peregrine solitons in a defocusing Kerr medium, the availability of giant peak amplitude for the bright–bright soliton pair, and the existence of so-called bright–dark soliton pair. The evolution dynamics of the algebraic two-soliton state toward a spliced single soliton is also discussed. 相似文献
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We present a novel system of a Gaussian soliton generation using a 1.30 μm optical pulse in a nonlinear micro-ring resonator system, which can be used to form the soliton pulse trains within the new wavelength band. By using the suitable parameters, the soliton pulse trains with the center wavelength at 1.30 μm can be generated after the intense Gaussian pulse is input into the nonlinear micro-ring resonator system. The initial pulse bandwidth is enlarged and the signal amplified by the nonlinear Kerr effects type within the ring resonator. The simulation values are used associating with the practical device parameters, whereas the obtained results have shown that the wavelength enhancement of the center wavelength can be achieved. Furthermore, the maximum soliton output power of 12 W is obtained, which is available to perform the long-distance communication link. The common problem of soliton dispersion is minimized by the zero dispersion condition in this case. The major advantage of the proposed system is that the dense wavelength division of the center wavelength with the spectral width of 7.0 pm (10−15 m) and the free spectrum range of 400 pm can be generated and achieved. This is available for the used/installed wavelength enhancement, which can provide more available channel capacity in the existed public optical network. 相似文献