Optimization of the peak power of doubly Q-switched lasers with both an acousto-optic modulator and a GaAs saturable absorber

The key parameters of an optimally coupled doubly Q-switched laser are determined by maximizing the peak power. A group of general curves are generated by considering the single-photon absorption (SPA) and two-photon absorption (TPA) processes in the GaAs, along with the Gaussian spatial distributions of the intracavity photon density, the initial population-inversion density and the influence of the acousto-optic (AO) Q-switch. These results are compared with the results obtained when maximizing the output energy of the doubly Q-switched laser, and the differences between these approaches are discussed. Sample calculations for a laser-diode-pumped Nd3+:YVO4 laser with both an AO modulator and a GaAs saturable absorber are presented to demonstrate the use of the curves and the relevant formulas.