Research Of Polarization Rotation Erbium-doped Fiber Ring Laser

Ultra-short pulse fiber lasers have been shown great potential application in nonlinear optics and ultrafast optics, especially in OTDM/WDM systems. Nonlinear polarization evolution (NPE) mode-locking technique is one of the best choices for fiber lasers to generate ultra-short pulses, with a number of advantages including compact and simple structure, self-starting, high stability, and so on. It could be widely used in other area, due to its wavelength tunability. With this in mind, this dissertation is focused on polarization rotation erbium-doped fiber ring laser which includes:1. The research status and development of the mode-locking fiber laser and tunable fiber laser is reviewed in this dissertation. The advantages of different mode-locking techniques have been analyzed.2. From the time-domain mode-locking master equation, the physical mechanism of nonlinear polarization evolution mode-locking is analyzed in theory, and the effect of cavity losses, dispersion, self phase modulation and the saturable absorber have been discussed. With the nonlinear SchrOdinger equations, the self-starting and stability of mode-locking fiber laser have been analyzed. The influence of cavity parameters on the characteristics of self-starting is investigated.