Collisions of Two Soatial Solitons in Inhomogeneous Nonlinear Media

Collisions of spatial solitons occurring in the nonlinear Schroeinger equation with harmonic potential are studied, using conservation laws and the split-step Fourier method. We find an analytical solution for the separation distance between the spatial solitons in an inhomogeneous nonlinear medium when the light beam is self-trapped in the transverse dimension. In the self-focusing nonlinear media the spatial solitons can be transmitted stably, and the interaction between spatial solitons is enhanced due to the linear focusing effect （and also diminished for the linear defocusing effect）. In the self-defocusing nonlinear media, in the absence of self-trapping or in the presence of linear self-defocusing, no transmission of stable spatial solitons is possible. However, in such media the linear focusing effect can be exactly compensated, and the spatial solitons can propagate through.     

Self-Similar Hermite-Gaussian Spatial Solitons in Two-Dimensional Nonlocal Nonlinear Media

We study analytically and numerically the propagation of spatial solitons in a two-dimensional strongly nonlocal nonlinear medium. Exact analytical solutions in the form of self-similar spatial solitons are obtained involving higher-order Hermite-Gaussian functions. Our theoretical predictions provide new insights into the low-energy spatial soliton transmission with high fidelity.     

对数型非线性电介质中的一维空间亮孤子

研究了对数型非线性电介质中空间亮孤子，认为对数型电介质中可支持亮空间孤子，并对其束宽变化作了分析，指出其束宽变化与光源峰值功率成反比：当功率较低时，束宽随功率的增大而急剧减小，表现出良好的非线性效应；当功率不断增大时，束宽的减小趋势逐渐放慢直至停止，对数型材料呈现饱和特性。     

强非局域非线性介质中的超高斯空间光孤子族

运用变分法,对任意实对称响应函数泰勒级数展开取至二阶,得到了1 1维强非局域非线性介质中光束传输的超高斯光束的近似分析解,提出了超高斯空间光孤子族模型。分析结果表明:束宽解是三角函数型,相移、空间啁啾以及临界输入功率都正比于超高斯光束的阶数,束宽振荡周期不仅与介质材料有关,而且还与光束和相位因子的阶有关。提出了准方波形空间光孤子的可能性。     

低振幅中心对称光折变暗和灰空间孤子的时间特性

为了研究中心对称光折变晶体中低振幅暗和灰空间孤子的时间特性,推导出了含时间参量的空间电荷场和光波的动态演化方程.采用数值方法,得到了中心对称光折变晶体中低振幅空间暗和灰孤子强度包络和强度半峰全宽的时间演化特性.结果表明,初始阶段形成的宽度较宽的孤子,其宽度随时间单调递减到一个最小值直至稳态孤子的形成;在相同的演化时间内...     

光折变有机聚合物中的双色光空间孤子

对光折变有机聚合物中的双色光空间孤子进行了理论分析,证明双色信号光的两个频率成分相互作用可以在折射率改变为正的光折变有机聚合物中形成暗暗和亮暗空间孤子,在折射率改变为负的光折变有机聚合物中形成亮亮和亮暗空间孤子。与单色光孤子的情况不同,对于双色光孤子情况,通过与一形成暗孤子的频率成分相互作用,另一频率成分在折射率改变为正的有机聚合物中也可形成亮孤子;通过与一形成亮孤子的频率成分相互作用,另一频率成分在折射率改变为负的材料中也可形成暗孤子。     

双光子光折变介质中光伏空间孤子

基于双光子光折变介质中空间孤子的统一理论,采用数值模拟的方法,比较了双光子光伏光折变介质中开路光伏空间孤子、短路光伏空间孤子和闭路光伏空间孤子的特性.结果表明:双光子光伏光折变介质中,闭路暗光伏孤子所需非线性要比开路暗光伏孤子所需非线性小,同时暗光伏空间孤子的半峰全宽随着负载电阻的增加而加宽;亮光伏空间孤子的形态与负载电阻基本无关.     

Double Humped Grey and Black Solitons in Kerr Nonlinear Media

The existence of a new class of double humped grey and dark solitons in a Kerr nonlinear medium has been predicted in this paper. Following well known variational procedure, the dynamics of the propagating soliton has been converted to a Hamiltonian formulation. A set of ordinary differential equations is then derived, which was subsequently examined to predict the existence of double humped grey and dark solitons. Linear stability analysis, numerical appreciation and phase plane dynamics show that these solitons are stable.     

Dissipative Vortex Solitons in Defocusing Media with Spatially Inhomogeneous Nonlinear Absorption

In this paper, by solving a complex nonlinear Schr¨odinger equation, radially symmetric dissipative vortex solitons are obtained analytically and are tested numerically. We find that spatially inhomogeneous nonlinear absorption gives rise to the stability of dissipative vortex solitons in self-defocusing nonlinear medium in the presence of constant linear gain. Numerical simulation reveals the interaction effect among linear gain and nonlinear loss in the azimuthal modulation instabilities of these vortices suppression. Apart from the uniform linear gain indeed affects the stability of vortex in this media, another noticeable feature of current setup is that the steep spatial modulation of the nonlinear absorption can suppress sidelobes effectively and support stable vortex solitons in situations with uniform linear gain.Under appropriate conditions, the vortex solitons can propagate stably and feature no symmetry breaking, although the beams exhibit radical compression and amplification as they propagate.     

向列相液晶中强非局域空间光孤子的实验观察

通过实验对向列相液晶中的非局域空间光孤子的传输进行了研究。理论上基于非线性的液晶孤子传输方程,采用高斯形式的试探解,得到了孤子传输的解析解,以及对液晶中的非局域孤子和Snyder等提出的强非局域孤子模型的结果进行了比较。实验上,观察了空间光孤子在向列相液晶中的传输,找到了不同束宽下空间光孤子的临界功率。比如束宽为2μm时临界功率为2.0mW。观察了向列相液晶中空间光孤子的弛豫过程,并注意到液晶分子的响应时间长达几秒钟,液晶中的孤子形成速度较慢。     

亚强非局域介质中的超高斯空间光孤子族研究

研究了亚强非局域介质中超高斯光束的传播特性.运用变分法,对任意实对称响应函数泰勒级数展开取至四阶,得到了1+1维亚强非局域非线性介质中光束传输的超高斯光束的近似分析解.分析结果表明：束宽解是椭圆雅可比双周期函数,相移、空间啁啾以及临界输入功率都正比于超高斯光束的阶数.提出了超高斯空间光孤子族模型和准方波形空间光孤子的实现可能性.     

线性聚焦和线性散焦效应对空间光孤子间相互作用的影响

考虑非均匀一维自聚焦介质的横向不均匀性,利用非线性薛定谔方程满足的守恒律给出了相邻空间孤子间隔的解析式,并对空间孤子之间的相互作用进行了数值模拟.结果表明,线形聚焦效应增强了空间孤子之间的相互作用;而线形散焦效应减弱了空间孤子之间的相互作用.当不考虑介质横向不均匀时,空间孤子之间发生周期性的碰撞.线性散焦效应使相邻空间孤子之间的间隔随传输距离发生周期性的变化,但孤子之间并不发生碰撞.线性聚焦效应使相邻空间孤子随传输距离发生周期性的碰撞,线性聚焦效应具有压制损耗使相邻空间孤子间隔变大的作用.     

Evolution of Bright Screening-photovoltaic Spatial Optical Solitons

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｓｐａｔｉａｌｓｏｌｉｔｏｎｓｉｎｐｈｏｔｏｒｅｆｒａｃｔｉｖｅｍｅｄｉａｈａｖｅａｔｔｒａｃｔｅｄｍｕｃｈｉｎｔｅｒｅｓｔｉｎｔｈｅｐａｓｔｆｅｗｙｅａｒｓ[1～ 10 ] .Ａｔｐｒｅｓｅｎｔ,ｔｈｒｅｅｔｙｐｅｓｏｆｓｃａｌａｒｓｏｌｉｔｏｎｓ ( ｑｕａｓｉ ｓｔｅａｄｙ ｓｔａｔｅ[1～ 3 ] ,ｓｃｒｅｅｎｉｎｇ[4～ 8] ａｎｄｐｈｏｔｏｖｏｌｔａｉｃｓｏｌｉｔｏｎｓ[9～ 10 ] )ｈａｖｅｂｅｅｎ ｐｒｅｄｉｃｔｅｄａｎｄｆｏｕｎｄ .Ｓｏｆａｒ ,ｐｈｏｔｏｖｏｌｔａｉｃｓｏｌｉｔ…     

Two-Dimensional Spatial Solitons in Nematic Liquid Crystals

We study the propagation of spatial solitons in nematic liquid crystals, using the self-similar method. Analytical solutions in the form of self-similar solitons are obtained exactly. We confirm the stability of these solutions by direct numerical simulation, and find that the stable spatial solitons can exist in various forms, such as Oaussian solitons, radially symmetric solitons, multipole solitons, and soliton vortices.     

双光子光折变晶体中两分量矢量空间孤子(英文)

为了研究外加偏压双光子光折变晶体中的矢量空间孤子,建立了矢量空间孤子的动态演化方程,给出了矢量空间孤子数值解.采用数值模拟的方法,求解矢量空间孤子的数值表达式,理论预言了稳态条件下亮-亮、暗-暗自耦合矢量空间孤子的存在;同时,数值求解演化方程,分析了亮-亮自耦合矢量空间孤子的演化特性.数值结果表明,无论两孤子分量的强度近似相等还是有较大差别,这些自耦合矢量空间孤子都可以由数值积分程序给出.亮-亮、暗-暗自耦合矢量空间孤子在双光子光折变晶体中稳定存在.     

Nonlinear All-Optical Switching Device by Using the Spatial Soliton Collision

We propose a new nonlinear all-optical switching device by using the spatial solitons collision. This is 1 × N switching device controlled by two control beams. The numerical results show that this device could really function as a 1 × N all-optical switching device. This device is a potential key component in the application of optical signal processing and optical computing systems.     

Nonlinear All-Optical Switching Device by Using the Spatial Soliton Collision

We propose a new nonlinear all-optical switching device by using the spatial solitons collision. This is 1 × N switching device controlled by two control beams. The numerical results show that this device could really function as a 1 × N all-optical switching device. This device is a potential key component in the application of optical signal processing and optical computing systems.     

有偏压中心对称光折变晶体中的屏蔽孤子

给出了中心对称光折变晶体中屏蔽孤子的高阶空间电荷场.当高阶项可以忽略时,这个电荷场就变为早前在中心对称光折变晶体中研究的屏蔽孤子的空间电荷场.研究了中心对称光折变晶体中屏蔽孤子的高阶非线性波动方程.在适当的条件下,这个非线性波动方程能够展示明暗空间光孤子.这类晶体不同于非中心对称晶体,其非线性折射率的改变来源于二次电光效应,而不是一般的线性电光效应.应用光束传播的方法,对这些孤子的稳定性进行了讨论.表明在小的微扰下这类孤子是稳定的,不会发生分裂.     

双光子光折变晶体中两分量矢量空间孤子

为了研究外加偏压双光子光折变晶体中的矢量空间孤子,建立了矢量空间孤子的动态演化方程,给出了矢量空间孤子数值解.采用数值模拟的方法,求解矢量空间孤子的数值表达式,理论预言了稳态条件下亮-亮、暗-暗自耦合矢量空间孤子的存在|同时,数值求解演化方程,分析了亮-亮自耦合矢量空间孤子的演化特性.数值结果表明,无论两孤子分量的强度近似相等还是有较大差别,这些自耦合矢量空间孤子都可以由数值积分程序给出.亮-亮、暗-暗自耦合矢量空间孤子在双光子光折变晶体中稳定存在.     

弱光强空间屏蔽光伏明孤子的动态演化特性

在忽略晶体损耗和扩散效应的情况下，讨论了加外电场的光伏光折变晶体中弱光强空间屏蔽光伏明孤子及其演化特性，在弱光强条件下得到了空间屏蔽光伏明孤子的解析解表达式，与运用数值计算的方法所得到的结果十分吻合，该方法解决了以往数值求解动态演化方程时必须先数值求解常数分方程或积分方程的问题，讨论了参量失配情况下空间屏蔽光伏明孤子的动态演化特征。