Manakov solitons in biased photorefractive polymer

The coupled equations for the incoherently coupled soliton pairs in biased photorefractive polymer are provided. It is shown that the coupled soliton equations reduce to Manakov equations when the total intensity of two coupled solitons is much lower than the background illumination. The bright-bright, dark-dark, and grey-grey soliton pair solutions of these Manakov equations are obtained, and the characteristics of these Manakov solitons are also discussed.     

One-dimensional optical bright screening photovoltaic photorefractive solitons, soliton pairs and incoherent interaction between them in BaTiO3 crystal

By the use of theory of optical solitons, nonlinear equations governed by screening photorefractive photovoltaic solitons are introduced. By means of numerical methods, intensity profile, refractive index change of the media and also stability under propagation are investigated. Self-bending of solitons under first-order diffusion is also studied. Besides, incoherent coupled bright-bright soliton pairs and incoherent interaction are studied.     

Superposition solitons in two-component Bose-Einstein condensates

We develop the Hirota bilinear method and obtain the exact one and two superposition soliton solutions for two-component Bose-Einstein condensates. The conversion of three kinds of solitons including the superposition solitons, bright-bright solitons, and dark-bright solitons is discussed. With the energy analysis, we find that the superposition soliton state is an excitation state for this system. Moreover, the collision of two superposition solitons is found to be elastic.     

Incoherently coupled two component screening photovoltaic solitons in two-photon photorefractive materials under the action of external field

The existence of incoherently coupled two-component steady state photovoltaic solitons in biased two-photon photorefractive materials due to two-photon photorefractive effect has been investigated. In the steady state regime, these incoherently coupled solitons can propagate in bright–bright, dark–dark and bright–dark configurations. The most important finding is that, with the application of electric field, it is possible to generate solitons and control them in those media where soliton formation was hitherto prohibited. Dynamic evolution of these solitons has been examined using numerical simulations, which show that these solitons are stable.     

Separate spatial soliton pairs in a biased series centrosymmetric photorefractive crystal circuit

It is shown theoretically that three types of separate soliton pairs: bright-bright, bright-dark, and dark-dark, can be established in a biased series circuit consisting of two centrosymmetric photorefractive crystals and the two solitons in a separate soliton pair can affect each other by the light-induced current. The effects of the intensities of soliton beams and background lights on the normalized profiles of solitons are discussed.     

光晶格势阱中二元凝聚体的矢量孤子的振荡和分裂

考虑外部囚禁势阱为光晶格势阱,研究了二元玻色-爱因斯坦凝聚体中亮-亮孤子的动力学行为.结果表明,亮-亮孤子的运动方向和振荡行为可以分别通过调节光晶格势阱的晶格常数和势阱深度来控制.进一步地,亮-亮孤子还可以被局域在光晶格势阱中,并且随着势阱深度的增加,局域孤子会产生分裂行为.     

Separate spatial soliton pairs in an unbiased series two-photon photorefractive crystal circuit

Dark (bright) steady-state spatial solitons are predicted in one dimension for a series circuit consisting of two two-photon photorefractive crystals of which at least one must be photovoltaic. Each crystal can support a spatial soliton. The two solitons are known collectively as separate spatial soliton pairs with three types: dark-dark, bright-dark and bright-bright. In the limit in which the optical wave has a spatial extent much less than the width of the crystal, the dark soliton can affect the other soliton by light-induced current, but the bright soliton cannot affect the other soliton in the soliton pair.     

Moving Matter-Wave Solitons in Spin-Orbit Coupled Bose-Einstein Condensates

We investigate the moving matter-wave solitons in spin-orbit coupled Bose-Einstein condensates(BECs) by a perturbation method.Starting with the one-dimensional Gross-Pitaevskii equations,we derive a new KdV-like equation to which an approximate solution is obtained by assuming weak Raman coupling and strong spinorbit coupling.The derivation of the KdV-like equation may be useful to understand the properties of solitons excitation in spin-orbit coupled BECs.We find different types of moving solitons:dark-bright,bright-bright and dark-dark solitons.Interestingly,moving dark-dark soliton for attractive intra- and inter-species interactions is found,which depends on the Raman coupling.The amplitude and velocity of the moving solitons strongly depend on the Raman coupling and spin-orbit coupling.     

Manakov solitons in centrosymmetric photorefractive crystals due to two-photon photorefractive effect

We present a theoretical study on incoherently coupled soliton pairs in two-photon centrosymmetric photorefractive crystals under steady-state conditions. It is shown that the bright-bright, dark-dark and bright-dark Manakov soliton pairs can be generated in two-photon centrosymmetric photorefractive crystals when the total intensity of two soliton components is much lower than the dark irradiance.     

双光子光折变晶体串联回路中独立全息屏蔽空间孤子对

为了得到双光子独立全息屏蔽空间孤子对的结果,基于光折变晶体中的两波耦合和双光子光折变效应,证明在由两块双光子光折变晶体和一个电压源通过导线连接组成的串联回路中存在全息亮(暗)屏蔽孤子。每块晶体中能支持一个全息屏蔽孤子,这两个孤子称为双光子独立全息屏蔽孤子对,有明-明、暗-暗和明-暗三种类型。数值计算结果表明,在光束的空间展宽远小于晶体宽度的极限条件下,孤子对中的两孤子通过光电流和相互耦合能影响到这些孤子的空间包络和动态演化特性。     

双色光光伏空间孤子的形成条件及其应用

以折射率改变为正的光伏晶体为例，讨论在其中形成双色光光伏空间孤子的条件-一般而言，在满足上述条件的情况下，双色光可以形成双色光亮孤子、双色光暗孤子、一亮一暗孤子-对于一个波长的光（ray2）单独不能形成亮孤子（它的Glass系数与背景光的Glass系数之比R2小于１）的情况，如果再加上一束另一个波长的光（ray1），且其Glass系数与背景光的Glass系数之比R1大于１，则在一定条件下，这个双色光中两个颜色的光可以都形成亮孤子-还讨论了ray1的光强对孤子宽度的影响- 关键词： 双色光 光伏 空间孤子 全光开关     

空间非相干多分量光束构成的非相干耦合屏蔽孤子对

两束本身具有空间非相干性的非相干多分量光束可以在光折变介质中形成非相干耦合 屏蔽孤子对，利用相干密度法得到了亮 亮、暗 暗型耦合孤子对的解，并研究了构成 非相干孤子对分量光束的相干组分的传播特性. 关键词： 空间非相干多分量光束 耦合孤子对 相干密度 相干组分     

Incoherently coupled photorefractive bright-bright soliton pairs in one and two dimensions

We investigate incoherently coupled bright-bright soliton pairs in photorefractive crystals under steady-state condition in both one and two transverse dimensions. The novel numerical scheme according to the Crank-Nicholson method generalized in three dimensions accompanied by the central difference method was used to solve the coupled wave and potential equations in order to find soliton solution and pairs distribution. Simulation of propagation is performed numerically and show that the presence of both components is required for stable propagation. This simulation approach demonstrates beams evolution after decoupling clearly.     

Incoherently coupled Gaussian soliton pairs in biased centrosymmetric photorefractive crystals

The coupling between two mutually incoherent Gaussian beams that propagate collinearly in biased centrosymmetric photorefractive crystals is investigated. It is shown that incoherently coupled bright-bright spatial soliton pairs can be formed by employing paraxial ray approximation. The physical properties of these soliton pairs are also discussed.     

有外加电源的串联光折变晶体回路中的独立空间全息-哈密顿屏蔽孤子对

在由两块垂直于光轴两端面镀上电极的光折变晶体和一个外加电源组成的串联光折变晶体回路中, 在适当的条件下可以形成独立空间全息-哈密顿屏蔽孤子对. 这种孤子对共有四种类型:明-明、暗-暗、明-暗以及暗-明. 当入射光束的空间展宽尺寸远小于晶体宽度时, 孤子对中的哈密顿暗孤子可以通过光感应电流影响另一个孤子, 而哈密顿明孤子和全息孤子则不能影响另一孤子.     

Spatial optical solitons in inhomogeneous elliptic core saturating nonlinear fiber

We have investigated the propagation characteristics of spatial optical solitons in saturating nonlinear waveguide employing JWKB and paraxial ray approximation. We have obtained two second-order coupled nonlinear differential equations for transverse soliton widths of solitons. Threshold power for stable propagation of the beam has been calculated from these coupled equations. We have undertaken stability analysis, which predicts robustness of these solitons. Both guiding as well as antiguiding cases have been considered and shown that stable spatial soliton propagation is possible in both cases.     

Combined periodic wave and solitary wave solutions in two-component Boseben Einstein condensates

In this paper, the Jacobi elliptic function expansion method provides an effective approach to obtain the exact periodic wave solutions of two-component Bose-Einstein condensates. Exact combined bright-bright and dark-dark soliton wave solutions can be achieved in their limit conditions. We also obtain the different formation regions of combined solitons. Our results show that the intraspecies (interspecies) interaction strengths clearly affect the formation of dark-dark, bright-bright and dark-bright soliton solutions in different regions.     

有外加电源的串联光折变晶体回路中的独立空间全息-哈密顿屏蔽孤子对

在由两块垂直于光轴两端面镀上电极的光折变晶体和一个外加电源组成的串联光折变晶体回路中, 在适当的条件下可以形成独立空间全息-哈密顿屏蔽孤子对. 这种孤子对共有四种类型:明-明、暗-暗、明-暗以及暗-明. 当入射光束的空间展宽尺寸远小于晶体宽度时, 孤子对中的哈密顿暗孤子可以通过光感应电流影响另一个孤子, 而哈密顿明孤子和全息孤子则不能影响另一孤子.     

闭路光伏光折变聚合物中非相干耦合亮-暗空间孤子对

为了得到闭路光折变有机聚合物中存在非相干耦合亮-暗光伏空间孤子对,采用数值模拟的方法,对稳态情况下两束互不相干的光束,在闭路光伏光折变有机聚合物中的传播进行了研究。结果表明,具有相同偏振和相同波长的两束互不相干的光束,可在光伏光折变有机聚合物中形成非相干耦合亮-暗光伏孤子对。在给定适当参量或扰动不太大的情况下,孤子对中的亮孤子和暗孤子都能在光伏光折变有机聚合物中稳定传播。研究结果可为光折变有机聚合物空间孤子理论的发展提供理论依据。     

有分压电阻和e偏振非相干背景光辐照的光折变晶体中非相干耦合空间孤子对

为了得到光折变晶体中非相干耦合空间孤子对统一理论的结果,基于单光子光折变空间光孤子的基本理论模型,建立了稳态条件下有分压电阻和e偏振非相干均匀背景光辐照的单光子光伏光折变晶体中非相干耦合空间孤子对理论.研究表明:这种孤子对是由两束偏振方向和波长都相同的互不相干光束耦合形成的,孤子对两光束都能在晶体中稳定传播;当分压电阻、e偏振背景光、外加电场和光伏场取不同值时,可获得14种光折变非相干耦合空间孤子对.本文的结果对完善和充实光折变空间孤子理论体系有重要意义.