Interaction of spatially overlapping standing electromagnetic solitons in plasmas

Numerical investigations on mutual interactions between two spatially overlapping standing electromagnetic solitons in a cold unmagnetized plasma are reported. It is found that an initial state comprising of two overlapping standing solitons evolves into different end states, depending on the amplitudes of the two solitons and the phase difference between them. For small amplitude solitons with zero phase difference, we observe the formation of an oscillating bound state whose period depends on their initial separation. These results suggest the existence of a bound state made of two solitons in the relativistic cold plasma fluid model.     

Effect of nonlinear inhomogeneity on the creation and annihilation of magnetic soliton

We employ the modified extended tanh-function (METF) method to solve the inhomogeneous nonlinear Schrödinger (INLS) integro-differential equation with nonlocal damping. We obtain a series of exact solitary solutions which found to support creation and annihilation of solitons accompanied by the shape changing property.     

Darboux transformation and novel solutions for the long wave-short wave model

Firstly, we establish the relation between the loop group method and gauge transformation method for 3×3 spectral problem. Some novel solutions of long wave-short wave model are obtained by Darboux transformation method. Besides, we give the analysis and classification of solution in detail.     

剩余三阶色散对相位共轭偏振孤子的影响及其补偿

光学相位共轭中剩余三阶色散不利于共轭孤子的稳定传输,导致孤子脉冲具有更大的时间抖动.本文提出在传输线末采用具有正三阶色散的色散位移光纤补偿光学相位共轭中的剩余正三阶色散.数值结果证明了其可行性.同时也分析其补偿的物理机制.     

Discrete solitons in zigzag waveguide arrays with different types of linear mixing between nearest-neighbor and next-nearest-neighbor couplings

We study discrete solitons in zigzag discrete waveguide arrays with different types of linear mixing between nearest-neighbor and next-nearest-neighbor couplings. The waveguide array is constructed from two layers of one-dimensional (1D) waveguide arrays arranged in zigzag form. If we alternately label the number of waveguides between the two layers, the cross-layer couplings (which couple one waveguide in one layer with two adjacent waveguides in the other layer) construct the nearest-neighbor couplings, while the couplings that couple this waveguide with the two nearest-neighbor waveguides in the same layer, i.e., self-layer couplings, contribute the next-nearest-neighbor couplings. Two families of discrete solitons are found when these couplings feature different types of linear mixing. As the total power is increased, a phase transition of the second kind occurs for discrete solitons in one type of setting, which is formed when the nearest-neighbor coupling and next-nearest-neighbor coupling feature positive and negative linear mixing, respectively. The mobilities and collisions of these two families of solitons are discussed systematically throughout the paper, revealing that the width of the soliton plays an important role in its motion. Moreover, the phase transition strongly influences the motions and collisions of the solitons.     

(1+1)维光折变亮屏蔽孤子相互作用的数值分析

利用束传播法对（1+1）维光折变亮屏蔽孤子间的相互作用进行了详细地数值模拟研究.结果表明：两同相孤子相互吸引,并伴有孤子融合现象,且孤子融合发生时的作用距离随着孤子初始间距的增大而增大;两反相孤子相互排斥,且排斥作用随着孤子初始间距的减小而增强;当两孤子的相位差位于区间（0,π）和（－π,0）中时,其相互作用过程将伴有能量转移,但两区间内能量转移的方向相反,并表现出反转对称性;由于孤子间的距离和相对相位对孤子间的相互作用均有很大的影响,因此多个孤子间的相互作用过程非常复杂,但可以通过分析相邻孤子间的相互作用对其进行定性的预测.     

Self-bending of photorefractive solitons

Self-bending of photorefractive solitons is caused by diffusion in photorefractive crystals and becomes an important effect when the beam size is in the range of the charge carriers diffusion length. In this paper we present an experimental and numerical examination of the beam bending dependence on relevant parameters such as the applied electric field and the beam intensity. We demonstrate that the bending dependence on the electric field in the low saturation regime has the form of a square function at low values of the field and becomes linear for higher values. For stronger saturation the curve gets the form of a square root function. The bending dependence on the beam intensity has a maximum at defined intensity. The experimental data are compared with numerical simulations, giving a good qualitative agreement.     

Bound soliton pulses in passively mode-locked fiber laser

A passively mode-locked soliton fiber ring laser was successfully demonstrated, and bound soliton pulses with an FWHM pulsewidth of 326 fs and fixed separation of 938 fs were first observed. The number of bound soliton pairs in the cavity can be controlled under lower pump power. The transmission effects were investigated by injecting bound soliton pulses into a single mode fiber.     

Investigation of soliton pairs in an erbium-doped fiber laser with large normal dispersion

We experimentally investigate the soliton pairs in a passively mode-locked erbium-doped fiber laser with large normal cavity dispersion. By adjusting the polarization state, four different kinds of soliton pairs are achieved. The pulses in soliton pairs exhibit different temporal separations, and show randomly distributed spikes on the top-flat of spectra. The pulse-pulse interactions in the soliton pairs are investigated, and it is suggested that the pulse separation, pulse duration, and their relative intensities all determine the strength of pulse interactions.     

mKdV-SineGordon方程的多孤子解

该文首先给出了mKdV-SineGordon方程的双线性形式和双线性Backlund变换,然后利用Hirota方法、Backlund变换方法和Wronskian技巧三种不同的方法分别得到mKdV-SineGordon方程的孤子解,最后验证了这三种解的一致性。