Study On Multi-wavelength Erbium Doped Fiber Laser Based On Stimulated Brillouin Scattering

Multiwavelength Erbium-doped fiber lasers (MW-EDFL) become the researchfocus because of the potential applications in optical fiber communication system,optical detection and so on. At room temperature Multiwavelength Brillouin-erbiumfiber lasers (MW-BEFL) is one of the effective methods to obtain Multiwavelengthlaser output. This kind of laser has advantages including narrow line-width, stablefrequency, directional sensitivity of the stimulated Brillouin scattering gain etc. In thisdissertation, the key technologies of MW-EDFL are analyzed based on summarizingvarious principle and implementation scheme. In short, we mainly carry out thefollowing several works:Firstly, we introduce the principle and experimental structure of several sorts ofMW-EDFLs and then analyze the key technology of suppressing the mode competitionin detail.Secondly, the three-level system of Erbium-doped fiber (EDF) is reasonablesimplified and promoted to fit multiple signal situation after the mathematic andphysical model for amplification is established. Meanwhile we particularly discuss twosignificant parameters: net cross section and overlap factor. Then, Brillouin scatteringtheory and the derivation of Brillouin threshold value are introduced in detail.Thirdly, the Brillouin ring laser theoretical thinking is proposed and then improved.After that, the method which putting intensity-dependent loss Sagnac ring mirror andtunable Sagnac filter into the laser cavity is presented. In addition, we evaluate thefiltering effect through simulation and experimental verification.Finally, a kind of handy MW-BEFL structure is designed. Meanwhile, we analyzethe mathematic and physical model of each component, and then propose a newiterative algorithm based on stimulated Brillouin scattering (SBS). After that,Multiwavelength laser output is investigated through Matlab simulation when settingparameters to different values. We observe the impact on output while changingBrillouin bump power, EDF pump power and pumps wavelength. In the optimumparameter setting condition, we can get more than25lasing line(s) of the simulationresults. We simultaneously carry on self-excited MW-BEFL experiment. Throughadjusting the polarization state of tunable Sagnac filter and EDF pump power, we canacquire18and16stable lasing line(s) in3dB bandwidth between1556-1558nm and1558.5-1560.5nm, respectively.