Study Of A Yb～(3+) Doped Double-clad Mode-locked Fiber Laser

In this thesis, theoretical and experimental study of Yb3+ doped double-cladmode-locked fiber laser was presented. The main contents are as follows:1. The development and merits of mode-locked fiber laser of threeconfigurations was introduced. A brief introduction on the application offemtosecond laser about medicine, physics, chemistry, military and so on waspresented.2. We solved rate equations of the fiber laser in cw condition. Detailed analysisof the mode-locking theory of femtosecond fiber laser was given.3. A theoretical investigation of parameters of self-similar pulse mode-lockingin a laser was presented. We analyzed the characteristic of self-similar pulseby numerical simulation of the nonlinear wave equation that governs pulsepropagation in most of the laser cavity. Stable self-similar pulses exist withenergies much greater than the soliton generating in mode-locked fiber laser,and this will have a better practical application.4. The parametric study of Yb3+ doped double-clad fiber laser using twodifferent fibers was performed, and the phenomena and results of theexperiment was presented. The best effort of the output power is fivehundred milliwatt, the wavelength is 1090nm and the output spectrum wasstable. On the basis of the foregoing studies, we analyzed the characteristicof self-pulsing in fiber laser.5. Taking SESAM as an output coupler, we realized Yb3+ doped double-cladQ-switching mode-locked fiber laser. The shortest period of the envelope ofthe Q-switched mode-locking is about 500ns and the average output power isabout 45mW. The repetition rate of the mode-locked pulse is about 26.7MHz.