The Research Of Acoustic-optical Q-switched Disk Laser(Yb:YAG)

The unique design of disk laser permits small heat effect, high conversion efficiency,high output power and good beam quality simultaneously. Combined with the Q-switchedtechnology, we can achieve high power, high repetition frequency, high energy and highquality output pulse. The technology of disk laser is not mature at present, and there areseldom researches about acousto-optic Q-switched disk laser. So it is necessary to analyzeand research acousto-optic Q-switched disk laser further.This thesis first analyzed the properties of Yb:YAG crystal, and the differentperformances which compared with the Nd:YAG crystal on crystal energy level structure,then sumed up the temperature influence of on Yb:YAG crystal.This thesis analyzed the pumping process and oscillating process in Q-switched processon the basis of rate equation, and calculated photo density and inverted population aboutquasi three-level with fast Q-switch. We estimated output parameters of Q-switchedYb:YAG disk laser. An important parameter-diffraction efficiency was derived, andformulas of four different conditions in acousto-optic Q-switched disk laser were given.Based on the theory, the experiment was carried out. In the experiment, we got42WQ-switched power with the repetition of10KHz, and the results were compared with thesimulation. We found that the pulse width was bigger as the pumping power increased, and itwas narrower as the repeat frequency increased, and the output power decreased as repeatfrequency increased. We analyzed the theory again, and built the model of slow Q-switch.The simulation of new model was able to correlate the observations of our experiment.