光相位共轭对分布放大明孤子传输的控制作用

应用数值分析方法研究了在由分布式掺饵光纤放大器级联的传输线中利用反相位、非等振幅输入和光相位共轭器等对孤子间的相互作用和孤子自频率漂移的削弱作用。结果表明,反相对相位、非等振幅输入和光相位共轭器的联合作用可以几乎完全消除几个ps脉宽孤子间的相互作用和孤子自频率漂移,避免了孤子间的能量交换,使孤子光脉冲在由分布式掺饵光纤放大器级联的长距离传输线中稳定传输。     

高码率光孤子传输系统中用光相位共轭补偿高阶扰动

在由分布式掺铒光纤级联的高码率传输系统中存在不可忽略的高阶扰动,它们引起孤子自频率漂移和孤子变形。本文用光相位共轭补偿高阶扰动,结果表明:由分布式掺铒光纤级联的高码率传输系统中,适当选取光相位共轭周期长度,可以完全消除高阶扰动引起的孤子自频率漂移和孤子变形。     

用于光孤子通信的理想分布式放大器

光孤子通讯的一个重要的问题是如何提高光孤子通讯的站间距离，降低线路成本，本文从降低信号在线路中的起伏入手，通过理论分析和计算机模拟，提出了用于孤子通讯的理想分布式光纤放大器的设想，借以降低噪声和提高泵浦站间距，降低线路成本，并对一些设计参数对系统的影响进行了讨论。     

偏振模耦合分布式光纤传感器空间分辨率研究

分析了偏振模耦合原理的分布式光纤传感器的自相干与互相干光；实验测量的干涉光证明了理论分析是正确的；利用偏振模耦合原理传感与白光干涉检测的分布式光纤传感器的空间分辨率是由光纤偏振色散系数与光源的谱宽决定的；由实验测量的偏振模耦合分布式光纤传感器的空间分辨率为6cm. 关键词： 光纤传感器 保偏光纤 空间分辨率 偏振模耦合     

白光干涉偏振模耦合分布式光纤传感器分析

分布式光纤传感器能够测量沿光纤长度上连续分布的外界量。用保偏光纤作为传感光纤的分布式光纤传感器,被测外界量引起保偏光纤中传播的两正交偏振模的相互耦合。用迈克尔逊干涉仪两臂光程差来补偿两个偏振模的光程差的方法探测传感信号。为了设计白光干涉偏振模耦合分布式传感器,根据统计光学原理分析了传感器的互相干特性。在此基础上分析了传感器的空间分辨力、光纤耦合点分辨力、最大传感光纤长度。波长1310nm、谱宽36nm的超辐射发光二极管(SLD)作光源．用色散参量为600ps／km,拍长3mm的保偏光纤的分布传感器空间分辨力和光纤耦合点分辨力分别为6cm和3mm。     

增益噪声对光孤子通信系统码率距离积的限制

在采用周期性能量补偿的全光孤子通讯系统中,比特率距离积受到孤子脉冲到达时间的Gordon-Haus效应的限制。本文讨论有损光纤中微扰对孤子群速度偏移的影响,分析集中式和分布式能量补偿方式下,增益噪声引起的孤子到达时间抖动,并由此得出系统的极限比特率距离积的大小。分析结果表明:在实际系统中,分布式能量补偿方式下系统极限比特率距离积一般要比集中式能量补偿方式下的高出一倍以上。 关键词：     

双折射光纤中色散管理孤子研究

研究色散管理孤子在双折射光纤中的传输特性.应用变分法分析并给出了双折射光纤中色散管理孤子参量演化的常微分方程.数值分析双折射对孤子参量的影响，分析发现在双折射光纤中色散管理孤子的宽度和啁啾不再是严格周期性变化.在色散管理的同时进行周期性偏振补偿可以消除走离效应，可以产生管理孤子.     

孤子色散管理传输及其在常规光纤通信中的可行性研究

从描述光纤中孤子脉冲传输的非线性薛定谔（NLS）方程出发，利用对称分步傅里叶方法对方程进行数值求解．研究了色散管理孤子（DMS）在常规光纤中的传输演化特性，分析了色散管理孤子在常规光纤通信系统中的可行性．结果表明，孤子在通过密集周期性搭配具有相反色散系数的光纤中传输，可以降低孤子间的相互作用，使得孤子的传输演化特性得到改善．利用色散管理来对常规光纤中光孤子脉冲之间的相互作用加以抑制，从而提高信息传输的比特率，但必须具有特殊的光纤制造工艺．     

位于第三近红外窗口的平坦光纤超连续谱产生

报道了一种基于非线性偏振旋转效应的被动锁模光纤激光器。采用980 nm分布式反馈激光器作为泵浦源,0.5 m长的高掺杂掺铒光纤作为增益介质。实现了脉冲宽度为822 fs的传统孤子锁模脉冲,输出脉冲的平均功率为2.8 mW,信噪比为55.8 dB。通过微调腔内的偏振控制器,实现了传统孤子脉冲和孤子分子脉冲间的切换,孤子分子的脉冲宽度为312 fs,信噪比为53.86 dB。孤子分子脉冲经掺铒光纤放大器放大后泵浦一段57 m长的高非线性光纤,产生了位于第三近红外窗口（1600 nm～1870 nm）的超连续谱,其20 dB谱宽为355.8 nm。     

孤子光纤中拉曼自频移效应的研究

首次报道孤子光纤中拉曼自频移效庆的研究结果。对满足孤子光纤色散关系条件时含损耗，拉曼延迟效应的广义非线性薛定谔方程进行了微扰分析。求得了拉曼自频移关系表达式。发现改变光纤几何参数可以有效地控制孤子拉曼自频移。     

基于级联型光纤的孤子自频移增强特性

设计了一种10m掺铥光纤级联于3m大模场光子晶体光纤末端的结构,利用400fs、1 550nm脉冲光产生孤子自频移,在入射光功率相同的情况下,掺铥光纤末端的孤子频移量比大模场光纤末端多100~150nm,平均多30%左右.孤子与泵浦光在掺铥光纤末端的输出光谱表明,残留泵浦光作用于Tm3+,在1.8~2.1μm范围产生受激辐射,从而增强了拉曼效应,导致孤子自频移增强.实验结果揭示了一种增强孤子自频移效应的方法,对于了解孤子在光纤中频移特性和提高基于孤子自频移的可调谐光源的调谐范围等具有参考意义.     

Trapping a dark soliton pulse within a nano ring resonator

We propose the interesting results that a dark soliton pulse can be localized within a nonlinear nano-waveguide. The system consists of nonlinear micro and nano ring resonators, whereas the dark soliton can be input into the system and trapped within the nano-waveguide. A dark soliton pulse is input into a ring resonator and chopped to be the smaller pulses. The required pulse is filtered and amplified, which can be controlled and localized within the nano-waveguide. The localized bright soliton is also reviewed and discussed.     

高阶耦合光伏空间孤子

采用数值模拟方法研究光折变晶体中的高阶耦合光伏空间孤子.该孤子可用包含两种频率的四束平行光入射到折射率改变为正的光折变晶体中形成.数值研究还发现，当入射光束为双曲正割光束时，在一定条件下可以模拟高阶耦合光伏空间孤子，而且，这种高阶耦合光伏空间孤子显示出光控光的特性.入射光束显著偏离左右对称会影响高阶耦合光伏空间孤子的实现. 关键词： 耦合光伏空间孤子 光控光     

A novel system for optically localized soliton pulse in a nano-waveguide

We propose a novel optical system that can be used to trap (store) light coherently. The system consists of two micro and a nano-ring resonators that can be integrated into a single system, which can be employed to generate the large bandwidth by a soliton pulse within a Kerr type nonlinear medium. The balance between dispersion and nonlinear lengths of the soliton pulse exhibits the soliton behavior known as self-phase modulation, which introduces the optical output (i.e. gain) constant, which means that light pulse can be trapped, i.e. localized coherently within the nano-waveguide. The time independent soliton pulse is adiabatically localized within the nano-ring device. Results obtained have shown that the trapping of the localized temporal and spatial soliton pulses is achieved.     

Soliton Properties of Light Pulses on the Surface of Ionic Crystals Generated by Strong Nonlinear Effects

In this paper, we theoretically discuss the soliton properties of light pulse transportation on the surface of an ionic crystal having strong nonlinear interactions between ions of unit cells. We analyze in detail the dark solitons when the nonlinear coefficient g is positive and negative, respectively. It is found that whether the nonlinear coefficient g is positive or negative, the dark solitons can be formed over the whole dispersion relation area of surface polaritons considering nonlinear effects. Attention should be paid to the fact that around ωTO, the light pulse can form advanced dark solitons, and there is a switching area from advanced dark soliton to retarded dark soliton near ωTO. We also discuss the effects of higher nonlinear dispersion on the solitons.     

Photons trapping within a nano-ring resonator controlled by light

We propose the interesting results that a bright and dark soliton pulse can be localized within a nonlinear nano-waveguide. The system consists of nonlinear micro- and nano-ring resonators, whereas the soliton pulse can be input into the system and trapped within the nano-waveguide. A soliton input is chopped by the nonlinear effects known as chaos into smaller pulses. The required pulse is filtered and amplified, which can be controlled and localized within the nano-waveguide. The localized bright and dark solitons are trapped within a nano-waveguide by controlling the nano-waveguide input power, which means that the photons trapping is controlled by light.     

Numerical investigation of slow solitons in Bragg gratings with a hyperbolic tangent apodization

This paper numerically and analytically investigates the formation and propagation motion of optical soliton in the Bragg grating.We choose the fibre Bragg grating with hyperbolic tangent apodization in the middle section in order to obtain slower solitons.Optical fibre soliton but not Bragg grating soliton is used as input pulse in the discussion,which is much more approximate to the light source for the practical purpose.We discuss in detail the effects of the soliton’s velocity with some parameters in the process of transmission.The results show that by choosing special parameters,one can make the soliton slow-down with a little distortion and energy decay and obtain tunable time-delay on a small scale.     

Motion characteristics of Bragg grating solitons in rectangle-apodized fiber Bragg gratings

We introduce both concave and convex rectangular apodizations in the middle of fiber Bragg gratings to achieve slow light. Based on the nonlinear coupled mode equations (NLCMEs), the transmission characteristics of grating solitons in rectangle-apodized gratings are numerically simulated and analyzed. The rectangular apodization can change the grating coupling coefficient to give rise to slow and capture the solitons in gratings. The effects of the soliton energy parameters, the width of rectangular apodization and the variation of the coupling coefficient on the soliton transmission are presented. The results show that, the velocity of solitons can be slowed down, and the capability to capture a soliton depends on the energy of input solitons, coupling coefficient, and the rectangular width. Two kinds of soliton capture methods are proposed and compared with each other.     

复色光光伏空间孤子

提出了双色信号光、单色背景光的光伏空间孤子理论,并获得了亮孤子解.用Cu:KNSBN晶体作介质,获得了复色信号光、单色背景光的复色光光伏空间亮孤子 关键词： 光伏空间孤子 复色光     

一维光学格子孤子的传输特性及控制研究

利用解析和数值方法研究了在具有横向折射率周期性调制的克尔型非线性介质中光学格子孤子的传输，得到了孤子参数的演化方程以及格子孤子的形成和稳定传输的条件.结果表明：当光束的入射角小于某临界角度时，光束可被类似波导形式的路径俘获而稳定传输，该临界角随折射率调制周期、调制深度的增加而增大，且光束越窄临界值越大.此外，线性空间啁啾虽然对光束传输的中心位置没有任何影响，但会导致光束发散从而破坏格子孤子的形成和稳定传输，对此提出了采用特定功率取值来补偿啁啾作用从而形成格子孤子的方案. 关键词： 光孤子 光学格子 光传输 矩方法