The Characteristic Research Of Acoustic-optical Q-Switched Yb:YAG Disk Laser

Diode-pumped disk laser has the advantages of high efficiency, high power and highbeam quality at the same time. So it is an important direction for the development ofsolid-state lasers. Due to the unique advantages of disk Yb: YAG crystal, disk lasers couldachieve high repetition rate, high peak power and high beam quality pulsed laser output.Thesis make the theoretical analysis for continuous acousto-optic Q-disk laser highbeam quality operation and stability of the cavity. We make theoretical analysis andexperimental research for high repetition frequency pulse stability and adjustableindependently output pulse width.Firstly did a certain theoretical analysis for the V cavity and simulated thermal focallength, endoscopic radius of curvature and the arm length and other factors on thefundamental mode spot and the stability of the resonator.Then calculated quasi-three level crystal’s photon number and inversion based on theequation for a Q-rate. Next we simulated the output characteristics of laser pulse are on thebasis of theoretical calculations. Focus on acousto-optic Q process appeared the pulseinstability as well as the increased instability of the pump power density higher startingfrequency. On this study we can adjust the output pulse width within a certain range on thecondition of certain pump power density and a certain repetition frequency by changingQ-switch opening time. This laid the foundation for the same pulse width under thecondition of different repetition frequencies.Finally made some experimental study on the acousto-optic Q-switch disk laser. Theexperimental results demonstrated unstable starting frequency of the output pulses increasedwith the pump power density increased under the conditions of a certain repetitionfrequency.But the increased speed is getting slower and slower, finally the unstable startfrequency value will slowly stabilize. Also proved that under the conditions of a certainpump power and repetition frequency, pulse width can be adjusted. With the Q-switchedopen slowly increase, the pulse width is also slowly increased and finally stabilized.