Research Of The Yb Doped Double-clad Pulse Fiber Laser

Double-clad fiber laser can be honoured as one of the twinkling stars in fiber laser family. The clad-pumping technology helped fiber laser shake off the impression of low-power. Double-clad fiber laser syncretize the high-power and high-quality of laser beam and all of the virtues of fiber laser. In addition, it can be easily applied in optic-communications. So it draws more and more attentions. The thesis details the research of the Yb³⁺ doped double clad fiber laser used in master-oscillator power amplifier(MOPA) system which pumped by Laser Diodes. The main theoretical and experimental researches are included in this thesis: (1) The state of the researches and the development way in the field of fiber laser worldwide are summarized based on comprehensive references reading, and the practical significance of this research subject is introduced. (2) The side-pumping structures especially which have been adopted in experiments are introduced. And an efficient and potentially robust side-coupling scheme have demonstrated. The couplerloss simulation as a function of tilt angle are showed in a graph. (3) Theoretical numerical analysis of the transient-state of the Yb³⁺ doped double clad fiber laser used in master-oscillator power amplifier (MOPA) system has been preformed. The pump power density distribution and reverse population density distribution, the effect of fiber length and input light pulse energy on output power have been analyzed. These result can be benefit for the design of MOPA's parameters such as fiber length, pump power and master-oscillator's power in experiment.