High Power AO Q-Switched Nd:YAG Laser

The object of this article is to output high repeat frequency and high peak power. Pulse laser generates from a Kr-lamp pumped solid state laser modulated by two AO switches. We studied it in both theory and experiment.The switch-losses of one Q-switch, two Q-switches in acoustic-field perpendicular or parallel are analyzed. According to the theory of acousto-optic (AO) interaction, the formulas of diffraction loss of two AO Q-switches, which acoustic-field are perpendicular or parallel one another, in normal Bragg diffraction are derived. The power divider for ensuring two AO Q-switch synchronization and effective power driving is designed. The calculation results are satisfied with Nd∶YAG laser experimental results. It is shown that two AO Q-switches, which acoustic-field are parallel, the switch-loss is more than one time than one AO Q-switch, and more than two times than one AO Q-switch when acoustic-field are perpendicular each other. Double acousto-optic devices two-dimensional Q-switch can efficiently improving the switch-loss of CW Nd:YAG laser. We designed power divider in order to ensure two AO Q-switch'signal in step, eliminated the redundant pulse and improved the laser power.In the experiment of 2KHz frequency, when the complexor of supersonic in the Q switch was normal, we got average power 103.5W, peak power 690KW, and the beam parameter product is 12mm. mrad. When the frequency was 10KHz, the average power was 163W, peak power was 96.5KW, and the beam parameter product is 14 mm .mrad.