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Investigation On The Novel Technology Of The Fiber Bragg Gratings And Applications In Optical Fiber Communications And Sensors

Posted on:2009-11-22Degree:DoctorType:Dissertation
Country:ChinaCandidate:J L ZhouFull Text:PDF
GTID:1118360272988798Subject:Communication and Information System
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Fiber Bragg gratings have become one of the most promising and representative optical passive devices at present,and have been broadly applied in optical fiber communications and sensors.The D-shaped fiber Bragg grating(D-FBG) and FBG based Fabry-Perot structure are two novel techniques,which can be applied in many areas for their special properties.So it is really important for theory and practical applications to study them.In this dissertation,the author investigates some problems in FBG techniques as follows:1.Investigation on the wavelength demodulation techniques of FBG and the applications.Two techniques of wavelength demodulation based on the linear edge filter and the tunable Fabry-Perot filter(FPF) are investigated.The experimental wavelength resolutions are 3.1pm,and 3pm,respectively.Then,both of them are cooperated and applied in the health monitoring of bridge structure.2.Study on the bending sensitivity of the D-FBG and its applications.The bending sensitivity of the D-FBG is analyzed with mechanics of material in detail.The experimental results are 78 times(compression) and 86 times(stretch) as high as the uniform FBG's,respectively.Then the D-FBGs are applied in sensors of linear displacement and acceleration,and the sensitivity of-0.27nm/mm and 0.191nm·s~2/m are obtained,respectively,in experiment.A novel method is proposed for tuning the grating's dispersion through bending the D-FBG into theΩ-shape in order to chirp it. The central wavelength of the D-FBG can be kept no shift by locating its center at the zero strain point.The bandwidth of the reflection spectrum is significantly tuned from 0.299nm to 2.057nm,while the central wavelength shift is within 17pm.3.Research work on the FBG based Fabry-Perot structure and its applications.The method for designing and fabricating the FBG based FPF is demonstrated concretely. Thus,such FPFs are applied in optical fiber ring laser and photonic generation of microwave.Nineteen single-wavelength lasings,eighteen pairs of dual-wavelength lasings,and a series of microwave signals with frequency from 9.4885GHz to 10.0712GHz are experimentally obtained,respectively.A novel tunable phase-shift FBG(PS-FBG) based on such Fabry-Perot structures is proposed.Two modes, including the 'ideal mode' and the 'practical mode',are created for simulation.The influence on the PS-FBG's transmission spectrum induced by the parameters is discussed.Compared with the traditional FBG-etching method,the sensitivity of such PS-FBG is much higher when it is applied in refractive index sensing.
Keywords/Search Tags:Fiber Bragg grating, wavelength demodulation, D-shaped fiber Bragg grating, Fabry-Perot filter, phase shift fiber Bragg grating
PDF Full Text Request
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