Pulse shape symmetry and pulse width reduction in diode-pumped doubly Q-switched Nd:YVO4/KTP green laser with AO and GaAs.

Using both acoustic-optic (AO) Q-switcher and GaAs saturable absorber, a diode-pumped doubly Q-switched Nd:YVO4/KTP green laser is realized for the first time to our knowledge. This laser can generate a symmetric and shorter pulse when compared with purely AO and passive Qswitching. A rate equation model is introduced to theoretically analyze the results obtained in the experiment, in which the spatial distributions of the intracavity photon density, the pump beam and the population-inversion density are taken into account. The numerical solutions of the rate equations are in good agreement with the experimental results.