Characteristics Of The Nonlinear Polarization Rotation Mode-Locked Fiber Laser

With the development of modern science and technology, fiber laser plays moreand more important role in the area of reach and development and widely using inindustry. Nonlinear Polarization Rotation (NPR) mode locked fiber lasers have beentaken into attention for a long time in the realm of industry because of manyadvantages like stability and high output power. In this paper we theoreticallydiscussed the characteristics of the NPR mode locked fiber lasers.(1) We introduce the theory of passive mode-locked fiber lasers in the chapter2.Analyzing the characteristics of the laser propagation in fiber, we establish a passivelymode locking equation. The characteristics of laser propagation in fiber including thedispersion and nonlinear effects which can affect the stability of mode locking andpulse chirp.(2) We described the influence of the devices in NPR mode locked fiber laser inchapter3. And we derived the effects of nonlinear polarization rotation which is thecombined results of each part of the devices in fiber lasers. The process of nonlinearpolarization rotation will influence the polarization states of the laser. At last weestablished a model to explain the process of self-starting in fiber lasers.(3) In chapter4we mainly studied the characteristics of mode locking pulsegenerated from NPR mode locked fiber lasers. We analyzed the effects of the fastsaturation absorber. The stability states of mode locked pulses came from the cavityparameters were discussed at the end of the paper.Further work was prompted and the experiment results are being demonstrated.