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Investigation On Fiber Bragg Grating Fabry-Perot Filter And Its Application In Tunable Narrow Linewidth Fiber Ring Laser

Posted on:2010-01-24Degree:MasterType:Thesis
Country:ChinaCandidate:M X ChenFull Text:PDF
GTID:2178360275994348Subject:Radio Physics
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Tunable single-longitudinal-mode fiber laser has attracted much interest due to its important applications in the fields of optical communication and sensing systems. Owing to the properties that the center wavelength of fiber Bragg grating (FBG) can be tuned by strain or temperature and that it is compatible with other optical fiber components, FBG has served as a wavelength selecting and tuning component in fiber laser.Fiber Bragg grating Fabry-Perot filter composed of two FBGs with a specific separation combines the advantages of both FBG and FP. Therefore, on one hand, FBG-FP is compatible with optical fiber components and can be tuned by strain or temperature like FBG. On the other hand, FBG-FP has resonance peaks with very narrow linewidth like FP. In recent years, some investigations reported that single-longitudinal-mode and narrow linewith fiber laser had been easily obtained by using FBG-FP filter as a mode selector.The thesis proposes that two FBG-FP filters with different but close free spectrum range (FSR) can function the same as a vernier by means of tuning one of the FBG-FP by strain. The working principle and mode selecting properties of the cascaded FBG-FP filters are discussed in detail.In this thesis, firstly, the fundamentals of both fiber laser and FBG are introduced. Fiber optical grating simulator for Bragg grating (FOGS-BG) analyzes FBG_based components based on transfer matrix method. The modal parameters for simulation are discussed and the characteristics of FBG-FP are investigated utilizing FOGS-BG. Then the simulation results of vernier principle based on two FBG-FP filters are also given.Under the guidance of previous theoretical analysis of vernier principle, two FBG-FP filters with respective average FSR of 97.1 pm and 76.8 pm were inserted in the ring cavity for fine mode selection in experiment. The number of cavity modes is tremendously suppressed and it is easier to obtain single-longitudinal-mode operation and narrow linewith laser. In the mean time, compared with single FBG-FP, the cascaded FBG-FP filters requires a smaller tuning and the tuning is quite effecient. Two configurations are proposed in the thesis and the comparison between them is discussed, too.
Keywords/Search Tags:Fiber laser, Fiber Bragg grating, Fabry-Perot filter, Vernier principle, Narrow linewidth
PDF Full Text Request
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