Study On High Repetition Rate Cr～(4+): YAG Passively Q-switched Laser

Passively Q-Switched lasers have more and more important applications in military affairs and civil affairs. But the investigations on passively Q-Switched lasers are always by numerical and experimental methods. In this paper, the stability of differential eguation has been related with laser dynamics. According as the characteristics of passively Q-switched laser elements, the two dimension differential eguations are got by means of adiabatic elimination approximation (AEA). A formula about the relationship between the important parameter-repetition rate of output pulses and laser's optical parameter has been obtained by means of Hopf bifurcation theory. The operation of lasers can be forecasted using this formula.The presence of saturable absorber also has influence on laser mode. In this paper, the transverse mode of laser has been researched, and the effect of mode selection has been validated.In this paper, the theoretical results have been validated by experiments. The experiment result of relation between the repetition rate of output pulses and pumping power is accord to theoretical result. In diode-pumped passively Q-Switched lasers, we can even get stable repetition output. And the mode of passively Q-Switched lasers is superior to active Q-Switched lasers. These results will benefit for passively Q-Switched laser's optimizing design, enhancing stability and increasing output power.