分类号：O437UDC：密级：公开编号：成都信息工程学院学位论文色散缓变光纤中的交叉相位调制不稳定性分析论文作者姓名：申请学位专业：电子科学与技术申请学位类别：工学学士指导教师姓名（职称）：论文提交日期：2009年06月01日色散缓变光纤中的交叉相位调制不稳定性分析摘要当同偏振不同波长的两光波在光纤中传输时，由于交叉相位调制和光纤中色散效应共同作用，可能导致交叉相位调制不稳定性产生，该现象在光开关、高重复率的脉冲串及超连续谱的产生等领域有重要应用，同时又是影响波分复用系统性能的重要因素。另外，色散缓变光纤同常规光纤相比，在光脉冲压缩和调制不稳定性产生孤子脉冲串方面显示出突出的优越性。利用色散缓变光纤能更有效地产生调制不稳定性，从而也更有利于调制不稳定性的相关应用。本文从光纤中耦合的非线性薛定谔方程出发，解析分析并计算模拟了色散缓变光纤正色散区交叉相位调制不稳定性产生的条件和增益谱，分析讨论了调制不稳定增益谱的谱宽和谱峰随入纤功率、色散缓变参数及损耗系数的变化规律。结果表明，在其它条件相同时，随着入纤功率的增加，增益谱的谱峰和谱宽都变大。而随着色散缓变参数的增大，谱宽变宽，谱峰几乎不变。随着损耗系数的增大，增益谱谱峰和谱宽皆减小。说明大的入纤功率及色散缓变参数有利于产生调制不稳定性，而损耗则相反。关键词：交叉相位调制不稳定性；色散缓变光纤；色散关系；增益谱AnalysisonCross-phaseModulationInstabilityinDecreasingDispersionFibersAbstractWhentwoopticalwaveswithsamepolarizationbutdifferentwavelengthspropagatinginopticalfibers,duetotheinteractionofcross-phasemodulationanddispersion,cross-phasemodulationinstabilitymayoccur.Thisphenomenoncanfindimportantapplicationinmanyfields,suchastheopticalswitching,generationofhighrepetitionrateofultra-shortpulsetrainsandsuper-continuousspectrum.However,thisphenomenonisalsoanimportantfactorwhichcanaffectconsiderablytheperformanceofwavelengthdivisionmultiplexing(WDM)opticalfibercommunicationsystem.Inaddition,incomparisonwiththeconventionalopticalfiber,thedecreasingdispersionfiber(DDF)embodiesobvioussuperiorityinopticalpulsecompressionandmodulationinstabilitygeneratedsolitonpulsetrains.ItismoreeffectivetogeneratemodulationinstabilityandmorebeneficialtoitsrelatedapplicationsbyusingDDF.Inthispaper,startingfromthecouplednonlinearSchrödingerequation,theconditionandgainspectraofcross-phasemodulationinstabilityareanalyzedandcomputersimulatedinthenormaldispersionregimeofthedecreasingdispersionfiber.Variationsofthegainspectraintermsoftheirwidthsandpeakvalueswiththeinputpowers,dispersionlongitudinalvaryingparametersandlosscoefficientsareanalyzedanddiscussed.Theresultsshowedthat,whentheotherconditionsarethesame,thepeakvaluesandwidthsofthegainspectrawillincreasewiththeinputpower.Withtheincreaseofdispersi