基于光纖光柵與光子晶體光纖傳感技術(shù)的研究.pdf

1、摘要摘要結(jié)合課題組天津市建工集團項目“光纖光柵傳感器測試建筑結(jié)構(gòu)應(yīng)變技術(shù)”和中國石化集團項目“常壓儲罐泄漏監(jiān)測系統(tǒng)開發(fā)”等對基于光纖光柵與光子晶體光纖的傳感技術(shù)進(jìn)行了理論與實驗研究。設(shè)計了基于圓環(huán)形薄壁截面梁(下面簡稱環(huán)形梁)的光纖布拉格光柵傳感結(jié)構(gòu)和基于雙金屬片的高靈敏度溫度傳感結(jié)構(gòu)，并對兩種傳感結(jié)構(gòu)進(jìn)行了理論與實驗研究。提出探測光子晶體光纖(photoniccrystalfiberPCF)橫向泄漏譜實現(xiàn)液體折射率傳感和利用多模光子晶

2、體光纖(multimodePCFMMPCF)實現(xiàn)彎曲傳感的思想，并對這兩種思想進(jìn)行了理論與數(shù)值分析，本文的主要內(nèi)容概括如下:在第一章中，概述了光纖光柵傳感技術(shù)的發(fā)展歷史、現(xiàn)狀和前景歸納了光纖光柵的寫入技術(shù)及其分類指出光纖傳感技術(shù)中I待解決的問題。在第二章中，詳細(xì)闡述了光纖光柵的禍合模理論簡要概述了分析光纖光柵的傳輸矩陣法和傅氏變換法理論分析了光纖光柵的應(yīng)力和溫度傳感原理，這些基本理論為我們設(shè)計光纖光柵傳感器提供了理論依據(jù)。在第三章中，設(shè)

3、計了基于環(huán)形梁的光纖布拉格光柵傳感結(jié)構(gòu)，井對其傳感特性進(jìn)行了理論與實驗研究。在第四章中，設(shè)計了一種基于雙金屬片的溫度增敏結(jié)構(gòu)，并從理論與實驗上對其溫度增敏機制進(jìn)行了研究。在第五章中，首先簡要介紹了BPM(beampropagationmethod)算法的基本理論思想隨后對光子晶體光纖做了概要性的介紹，了解折射率引導(dǎo)型和光子帶隙型光子晶體光纖的光學(xué)特性著重闡述了光子晶體光纖在傳感方面的應(yīng)用:最后使用BPM方法分析了光子晶體光纖的液體折射率

4、傳感和彎曲傳感特性。初步取得了如下創(chuàng)新性成果:(1)設(shè)計了基于圓環(huán)形薄壁截面梁(下面簡稱環(huán)形梁)的光纖布拉格光柵傳感結(jié)構(gòu)，對其傳感特性進(jìn)行了理論與實驗分析，實現(xiàn)了應(yīng)力的傳感、溫度與應(yīng)力同時傳感、溫度自補償?shù)睦鞲辛硗饫么藗鞲薪Y(jié)構(gòu)實現(xiàn)了帶寬和中心波長的獨立調(diào)諧并進(jìn)行了便攜結(jié)構(gòu)的設(shè)計。由于環(huán)形梁結(jié)構(gòu)簡單、方便、成本低廉有望在鋼管、鎖鏈等實際建筑結(jié)構(gòu)的健康檢測及波長可調(diào)諧功能器件中得到廣泛的應(yīng)用。(2)設(shè)計了一種基于雙金屬片的溫度增敏結(jié)構(gòu)

5、，將光纖Bragg光柵(fiberABSTRACTABSTRACTAccordingtheprojectsofTianjinConstructingCorporation蝙pticalfibergratingbaseddetectingtechnologyforconstructionstructureand#1rspectingsystemforstoringjarundernormalpressureweinvestigatedth

6、efiberBragggrating(FBG)andphotoniccrystalfiber(PCF)basedsensingtechnologyintheoreticallyandexperimentally.WedesignedloopthinwallsectionbeambasedFBGsensingstructureandbimetallicsheetsbasedFBGtemperaturesensingstructureand

7、demonstratedthemechanismsofthestructures.WealsoputforwardthattransverseleakspectrumofthePCFcanbeusedforsensingindicesofliquidsandmultimodesphotoniccrystalflber(MMPCF)canbeusedforsensingbendwhichhadbeenanalyzedintheoretic

8、allyandnumerically.Thechiefcontentofthedissertationarelistedasfollows:InthechapteronethedevelopmenthistoryactualityandforegroundoffibergratingsensingwereintroducedresumptivelyFBGfabricatingtechnologyandtheclassifywereals

9、ointroducedinparticulartheproblemsthatrequiringsolvedinFBGsensingtechnologywerepointedout.InthechaptertwothetheoryofFBGsensingareintroduced.CouplingmodetheoryhasbeenexpatiateddetaillyMatrixanalyzingmethodandFouriertransf

10、ormingmethodwereintroducedbrieflythestrainandtemperaturesensingmechanismswereanalyzedtheoretically.InthechapterthreewedesignedtheloopthinwallsectionbeambasedFBGsensingstructureanddemonstra宜editssensingmechanism.Inthechap

11、terfourwedesignedanovelstructurebasedonbimetallicsheetstoenhancetemperaturesensitivityofFBqandwealsoinvestigateditssensingmechanism.Inthechapterfivethebasicaltheoryofbeampropagationmethod(BPM)wasintroducedbrieflyfirstlya

12、ndthePCFwasintroducedincludingtheopticalpropertyoftotalinnerrefractiveandphotonicbandgapPCFthesensing即plicationsofPCFwereexpatiatedemphaticallyatlastrefractiveindexandbendsensingwerenumericallyanalyzedbasedontheBPM.Theel

13、ementaryinnovatingresultsaresummedupasfollows:(1)WedesignedtheloopthinwallsectionbeambasedFBGsensingstructureandrealizedstrainsensingtemperatureandstrainsensingsimultaneouslyforcesensingwithtemperatureselfcompensatedandi

14、ndependenttuningofthecenterwavelengthandthebandwidthofFBGbasedonthestructure.Thesensingstructureishopefultobeusedbroadlyinhealthcheckofbuildingandtuningapparatusforitssimplenessconvenienceandlowcost.(2)Wedesignedanovelst

15、ructurebasedonbimetallicsheetstoenhancetemperaturesensitivityofFBGThetwoendsofthebimetallicsheetswerefixedbyboltsandaFBGwaslongitudinallyadheredononeofthesheetswhoseexpansioncoeficientislargerthanthatoftheother.Thechange

16、oftemperaturemakesbimetallicsheetsnotonlyexpandingbutalsobendingwhichisthemechanismofenhancingFBGtemperaturesensitivity.Ifthebimetallicsheetsaremadeofaluminiumandironthetemperaturesensingcoefficientis0.08014nm0Cwhichis1.