铌酸锂晶体的研究与分析报告.doc

《铌酸锂晶体的研究与分析报告.doc》由会员上传分享，免费在线阅读，更多相关内容在应用文档-天天文库。

1、摘要本文基于新型线性电光效应耦合波理论，通过设定超晶格周期极化铌酸锂晶体倒格矢参数，从而弥补双折射时o光和e光折射率不同造成的相位失配。计算有效电光系数，推倒耦合波方程的解析解。并利用matlab进行线性仿真，研究温度，波长，外加电场和晶体占空比变化时对于电光效应中的转换效率的影响。仿真的数值结果表明：随着温度与相位匹配时对应的温度的差值的增大，相位失配量将增加，从而导致转换效率呈峰值逐渐降低的波动形式趋于零，当温度满足相位匹配时转换效率最高；此外晶体极化周期数量的增加，将使得转换效率的波动更加剧烈，其值也降低的更快，波动次数也将增多。改变波长的情况基本类似于温度

2、，仅在波动细节上有细微差距。而电场对转换效率的影响则是成正比的线性关系。此外我们所取的占空比约等于0.25和0.75时将可以使转换效率取到最大值。关键词铌酸锂；电光效应；耦合波；转换效率AbstractBasedonthenewwavecouplingtheoryoflinearelectro-opticeffect.BysettingthegratingwavevectorparametersofperiodicallypoledLiNbOcrystal,wecompensateforthephase-matchedwhichiscausedbydifferen

3、tindexofrefractionoftheo-rayande-raywhenbirefringencehappens.Wecancalculatetheeffectiveelectro-opticcoefficientofthesystem.Throughtheanalyticalsolutionofthewavecouplingequations,usematlabtodolinearsimulation,andstudyontheinfluenceoftheconversionefficiencyintheelectro-opticaleffectwhen

4、temperature,wavelength,electricfieldintensityandcrystaldutycyclechange.Numericalsimulationresultsshowthat,withtheincreasingdifferencemadebytemperaturewhichcorrespondstothetemperatureandphasematching,theamountofphasemismatchwillincrease.itresultsinanincreaseofphasemismatch,thuscausingt

5、heconversionefficiencytoassumethefluctuatingformtendingtozerowhichthepeakvaluereducesgradually;whenthetemperaturesatisfiesphasematch,conversionefficiencyisthehighest.Inadditionwhenthenumberofthecrystalpolarizationcycleincreases,thefluctuationoftheconversionefficiencywillbemoreviolent,

6、thevaluewillalsoreducefasterandthenumberoffluctuationswillincrease.Thesituationofthewavelengthissimilarwiththetemperature.Thereisjustonlylittlediscrepancyonthefluctuationindetailsoftheconversionefficiency.Buttheinfluenceoftheelectricfieldtotransferefficiencyistheproportionallinearrela

7、tionship.Inaddition,whenthedutycycleisequivalenttoabout0.75and0.25,theconversionratecanbetakentothemaximum.KeywordsLiNbO;electro-opticaleffect;coupledwave;conversionefficiency目录摘要IAbstractII第1章绪论11.1引言11.2电光效应的理论发展11.3研究方向和容21.4本章小结3第2章LiNbO晶体电光效应理论42.1电光效应基本椭球理论42.2LiNbO晶体的电光效应62.3周期

8、性极化Li