Experimental Of Diode-pumped Yb 3+ -doped Ultra-fast Lasers

With the development of laser diode technology, research on the diode-pumped solid state lasers has gained rapidly advancement. Due to the advantage of high efficiency, reliability and compactness, diode-pumped solid lasers have been widely used in various fields such as medical, national defense, industry processing and scientific researches. However, it remains a major task to develop various high performance diode-pumped solid state lasers. Current researches are focused on: ultra-fast solid state lasers and the new materials for solid state lasers.The dissertation follows the trend of the diode-pumped laser, we do some experimental studying on self-mode-locking lasers and passively mode-locking lasers, which used two new Yb3+-doped crystals (Yb:LSO,Yb:LYSO)as the laser materials. The contents can be outlined as follows:1. The history and progress of both the LD pumped solid state lasers and the mode-locked lasers are reviewed, as well as the advantages of Yb3+ materials and the development of mode-locked lasers based on Yb3+-doped crystal.2. Based on the mode-locking principle theory, the mechanism of self-mode-locking in the nonlinear crystal is analyzed, and the process of passive mode-locking by SESAM is described.3. Characteristics of Yb:LSO,Yb:LYSO laser crystals and mode-locking lasers are experimental researched. We study on LD pumped Yb:LSO/SESAM laser used W-cavity, 1.6W mode-locked laser output is obtained, and the pulses width is about 4.3ps. At the same times, we also study LD pumped Yb:LYSO passively mode-locked lasers, the output power was 2.13W, and the pulses width was about 3.9ps.4. In order to obtain the femtosecond laser pulses, a pair of SF10 prisms was inserted into the laser cavity for compensating the positive group-velocity. LD pumped Yb:LSO femtosecond lasers, the maximum output power was 800mW at the incident pump power of 14.44W, corresponds to a peak power of 11.0kW,the mode-locked pulses were compressed to 699fs. And the Yb: LYSO fs laser, the output power was1.03W with a peak power of 13.4W, the pulses width was compressed to 780fs.5. Experimental studied on LD pumped self-mode-locked lasers, which used Yb:LSO/Yb:LYSO as the laser crystals. In the experiment of the Yb:LSO self-mode-locked laser, we get the continuous wave mode-locking operation, the pulses width was 8.7ps at the center wavelength of 1058nm and the bandwidth was 1.6nm. The corresponding output power was 2.98W. Using the Yb:LYSO as the self-mode-locked crystal, high power and short pulses was obtained. 3.08W output power was achieved with the pulses duration 7.8ps.