【作者】 刘莹松；

【导师】 元秀华；

【作者基本信息】 华中科技大学 ， 光学工程， 2006， 硕士

【摘要】 光纤中存在的超连续谱现象源于光纤中各种效应的共同作用,包括群速度色散和自相位调制、交叉相位调制、四波混频及受激拉曼散射等。本文介绍了特种光纤中超连续谱现象的数值与实验研究的成果,基于色散平坦渐减光纤以及高非线性光纤给出了具体的数值研究与实验分析。主要内容如下:(1)介绍了光纤中脉冲传输的基本理论以及广义非线性薛定谔方程的推导过程,介绍了超连续谱研究的发展状况以及一些相关的应用。(2)介绍了光纤中超连续谱现象的物理基础,特别是光纤中的各种效应,包括光纤损耗、二阶群速度色散、三阶群速度色散以及高阶非线性效应等是如何影响超连续谱的。(3)提出了研究色散平坦渐减光纤中超连续谱现象的物理模型和数值计算方法。运用分布傅立叶方法求解了对应的广义非线性薛定谔方程,模拟了色散平坦渐减光纤中脉冲的传播演化过程和超连续谱产生的过程。分析结果表明,光纤的色散特性对于脉冲的演化以及超连续谱的产生有着关键的作用。同时,还讨论了包括泵浦脉冲功率、高阶群速度色散、高阶非线性效应以及初始脉冲啁啾对超连续谱现象的影响。(4)以高非线性光纤为对象,对该种光纤中的超连续谱现象进行了实验分析,并提出了一种利用普通单模光纤进行啁啾补偿来优化超连续谱谱宽的方案。更多还原

【Abstract】 The Supercontinuum (SC) spectrum phenomenon in fiber has been conjectured to be the interplay between Group-velocity dispersion (GVD) and fiber nonlinearity, such as self phase modulation, cross phase modulation, stimulated Raman Scattering and Four-Wave Mixing etc.In this thesis, numerical analysis based on Dispersion Flattened Decreasing Fiber (DFDF) and experiment study based on High Non-Linear Fiber (HNLF) of Supercontinuum are introduced. The main contents are as follows:(1) The development and applications of Supercontinuum spectrum are introduced. The basic theory of pulse propagation in fiber is introduced, and also the Nonlinear Schr?dinger equation (NLSE).(2) The physics foundation of the Supercontinuum phenomenon in fiber is discussed, especially those effects in fiber including fiber loss、GVD、TOD and higher-order non-linearity effects such as SPM, SRS, XPM etc. Then some kinds of fiber which are being used for Supercontinuum spectrum generation are introduced.(3)The principle and numerical model of Supercontinuum spectrum generation in the DFDF is presented. Split-Step Fourier methods are used to solve the NLSE in the DFDF, and the generation of Supercontinuum spectrum in the DFDF is simulated numerically. The analysis indicated that the dispersion characteristic of the DFDF fiber is crucial for the Supercontinuum spectrum generation. Also, the effects of the injected pump power、higher-order GVD、higher-order nonlinearity and input pulse chirp are considered.(4)A Supercontinuum spectrum generation experiment using HNLF is demonstrated. A chirp compensation method using SMF is introduced to generate more flattened and wide Supercontinuum spectrum.更多还原