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1、AbstractThemaincontentofthisthesisisdividedintothreeparts:transfermatrixtheoryanalysisoffiberBragggratings,transmissioncharacteristicsanalysisofuniformfiberBragggratingsandnumericalanalysisofdispersionpropertiesofchirpedlong-periodfibergratings(CLPFGs)basedontwofiberanalysismodels・Chi
2、rpedfibergratingsoffermanyadvantages,includinglowinsertionloss,compactness,lowcost,highdispersionvalue,therebypavingthewayforeffectiveandpracticaldispersioncompensation.Thegeneralopticalfibercanbeviewedasathree-layeredmediumcylindricalwaveguide,butbecauseofitseigen-valueequationandthe
3、fielddistributionofthecore-modeandcladding-modebasedonthethreelayeredmediummodelareconsiderablecomplex,usuallythetwo-layeredmediummodelisusedinstead・Inthecaseofthincladdinglayer,thedifferenceofthecore-modeeffectiverefractiveindex(RI)producedbythetwofiberanalysismodelsissignificant.By
4、meansofthecoupled-modetheoryandthetransfermatrixmethod,incombinationwiththedifferenceofthecore-modeRIsbasedontwofiberanalysismodels,thisthesismainlystudytransmissioncharacteristicsanddispersionpropertiesofthin-cladfibergratings.Thestudyinthethesisiscategorizedasfollows:(1)Forthepurpos
5、eofanalyzingaccuratelythetransmissioncharacteristicsofthin-cladfibergratings,thecontrastbetweentheeffectiveRIsofthecoremodeinanuniaxial-crystalfiberyieldedbytwofiberanalysismodelsisdemonstratedandanalyzed・Onitsbasis,theresonantwavelengthandbandwidthofthin-cladfiberBragggratingsareanal
6、yzedrespectively.Moreoverwesimulatetheresonantwavelengthandbandwidthofthin-cladlongperiodfibergratingsrespectively.Accordingtotheobtaineddata,transmissionspectrum,timedelayanddispersionoffiberBragggratings(FBGs)andlongperiodfibergratings(LPFGs)basedontwofiberanalysismodelsareanalyzed.
7、Theresultshowsthattheresonantwavelengthandbandwidthdifferenceproducedbythetwofiberanalysismodelsissignificant,especiallyinthecaseofthincladdinglayer,thesmallerthecladdingradiusis,thegreaterthedifferenceis.Furthermore,theinfluenceofthelengthofthefibergratingsandcross-couplingcoefficien
8、tonth