增益随机变化对分布放大暗孤子传输系统的影响

基于分布放大暗孤子传输系统的增益随机变化，利用守恒量扰动法，研究了增益随机变化对暗孤子到达检测窗口时间抖动的影响，结果表明，增益随机变化对暗孤子速度产生了影响。，并增大了暗孤以达时间的抖动，引入非线性增益可以有效抑制增益随机变化增大的暗孤子到达时间的抖动。     

拉曼散射与自陡峭效应对皮秒孤子传输特性的影响

通过求解包含拉曼增益和自陡峭效应的高阶非线性薛定谔方程, 运用MATLAB模拟了拉曼增益和自陡峭效应共同作用对孤子脉冲在各向同性光纤中传输特性的影响, 结果表明, 自陡峭效应会导致孤子产生时域位移, 而且会使高阶孤子产生孤子分裂现象. 与此同时, 拉曼增益改变了孤子的传输特性, 抑制了自陡峭效应, 从而导致脉冲宽度增大、脉冲偏移程度减弱、高阶孤子分裂成基阶孤子所需的传输距离增大.     

光纤的暗孤子传输特性研究

本文用行波法求解了光纤的暗孤子的NLS方程,由此孤子解讨论了暗孤子在光纤中的传输特性。     

脉冲内拉曼散射影响下的孤子之间的相互作用及其控制

研究了脉冲内拉曼散射效应影响下的同相和反相相邻孤子脉冲之间的相互作用,分析了孤子之间的相互作用对定时抖动的影响和脉冲内拉曼散射效应对孤子频移的影响。研究结果表明:在脉冲内,在拉曼散射效应的影响下,同相基态孤子脉冲的周期性离合被破坏了,两孤子脉冲一次碰撞后一直处于排斥状态,并且在碰撞后自频移现象十分明显;反相孤子脉冲的影响则较弱,两孤子脉冲都向下降沿发生偏移。引入非线性增益可以有效地控制孤子之间的相互作用,抑制自频移效应和稳定孤子传输。     

光孤子传输模型及其应用

从周期性集中放大系统孤子传输的基本方程出发，建立了比平均孤子模型适用范围更广、更精确的传输模型，运用微扰方法对孤子到达时间抖动作了研究，并与平均孤子模型给出的结果作了比较。     

拉曼增益对高双折射光纤中暗孤子俘获的影响

从高双折射光纤中含有拉曼增益的耦合非线性薛定谔方程出发, 利用拉格朗日方法, 推导出了暗孤子俘获的阈值, 并利用快速分步傅里叶变换, 模拟了孤子的两个正交偏振分量的演化, 对比了两种方法得到的阈值, 探究了暗孤子俘获受拉曼增益的影响. 研究发现解析解所得阈值比数值解偏小, 且群速度失配越小时, 二者符合得越好; 并且拉曼增益减小了暗孤子的俘获阈值, 当平行拉曼增益增大时, 俘获阈值减小加快.     

随机色散对孤子传输系统时间抖动影响

在分布放大传输系统中建立了随机色散模型,利用自伴算符法研究了随机色散的影响。结果表明:随机色散与放大的自发辐射噪音联合作用增大了传输系统的时间抖动,其中与传输距离有关的随机色散具有长距离效应,而与孤子频移有关的随机色散具有短距离效应。     

单模光纤中传输的长脉冲孤子

理论上证明了一种新的孤子可以在单模光纤中稳定传输，其波形为ｓｅｃｈ１／２（ｘ）。对于普通光纤，在工作波长为１．３μｍ处，当输入峰值功率为１Ｗ时，这种孤子脉冲的脉宽大约为１ｎｓ。     

非自治拉曼多色孤子的管理和传输

以变系数的非自治非线性薛定谔方程为模型,考虑了一种色散、非线性和自发拉曼散射效应管理下的非自治系统,通过简单变换显式给出了该系统的精确非自治拉曼多色孤子解。基于精确孤子解,解析研究了该拉曼多色孤子在非自治管理系统中的演化特性,发现孤子的中心位置、波数与色散和非线性以及拉曼效应有关,而孤子频移仅与拉曼效应的参数决定,拉曼效应主导了非自治孤子的自频移,引起了孤子的频移在传输过程中不断的发生变化,导致了孤子的多色性。另外,我们数值讨论了该非自治孤子的传输稳定性,结果表明:该非自治拉曼多色孤子在有限的扰动下具有较好的稳定性。     

高阶效应对孤子传输影响的研究

本文用特殊的数学技巧导出了高阶变形的NLS方程的直接孤子解。     

KTP离子交换光波导及特性

报道了制备Ｚ－切ＫＴＰＲｂ／Ｂａ离子交换平面光波导的方法，给出了较理想的Ｒｂ和Ｂａ的ｍｏｌ％比，测量了光波导层的光损伤感度和晶格常数变化。实验结果表明：光损伤感度为１．２～２．３×１０－１０ｃｍ２／Ｊ，它与掺Ｂａ的含量和热退火工艺无关；晶格常数的变化为０．４２～０．２５％，它随着掺Ｂａ含量的增加而减少。     

Dark Soliton Transmission in Twin-Core Fiber

Dark soliton transmission is investigated by numerical simulation in twin-core fiber. It is shown that the energy exchange between two cores relates to initial relative phases and initial relative amplitudes of input dark solitons, it may be of regular and apparent period, irregular period, or non-period, and the influence factors on beat length are analysed.     

The Influence of Dispersion Stochastic Variation on Bright Soliton Transmision System

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~ Transform Demonstration of Dark Soliton Solutions Found by Inverse Scattering

One of the basic problems about the inverse scattering transform for solving a completely integrable nonlinear evolutions equation is to demonstrate that the Jost solutions obtained from the inverse scattering equations of Cauchy integral satisfy the Lax equations. Such a basic problem still exists in the procedure of deriving the dark soliton solutions of the NLS equation in normal dispersion with non-vanishing boundary conditions through the inverse scattering transform. In this paper, a pair of Jost solutions with same analytic properties are composed to be a 2 × 2 matrix and then another pair are introduced to be its right inverse confirmed by the Liouville theorem. As they are both 2 × 2 matrices, the right inverse should be the left inverse too, based upon which it is not difficult to show that these Jost solutions satisfy both the first and second Lax equations. As a result of compatibility condition, the dark soliton solutions definitely satisfy the NLS equation in normal dispersion with non-vanishing boundary conditions.     

Influence of Stochastic Refractive Index Variation on Time Jitters

The model of stochastic refractive index variation is built in dark soliton transmission system, its influence is studied on time jitters. The results show: the stochastic variation apparently leads to the time jitters in arrival, and reduces the stability and the capacity of the transmission system.     

Time Jitters Caused by Randomly Varying Birefringence in Soliton Transmission System

Soliton propagation in fiber with randomly varying birefringence is studied by using self-companying operator method. It is shown that randomly varying birefringence leads to time jitters increasing with transmission distance, and disrupts the stability of soliton transmission. The fluctuation of time jitters is stochastic, and nonlinear gain is introduced to remove the influence.     

The influence of stochastic nonlinear gain variation on bright soliton transmission system

The model of stochastic nonlinear gain variation is built in the soliton transmission system. The influence of the stochastic nonlinear gain variation on the soliton transmission system is studied. The results show that the stochastic nonlinear gain variation apparently leads to the time jitters in arrival, degrades the capacity of soliton transmission system and the filter can suppress the influence well.     

Influence of Stochastic High-Order Perturbations on Soliton Transmission System

The influence of stochastic high-order perturbations on soliton transmission system is studied by self-companying operator method. Arrival time jitters variation induced by stochastic third-order dispersion is approximately proportional to three powers of transmission distance, that by stochastic nonlinear dispersion and self-steeping are approximately proportional to the transmission distance.