Doubly Q-switched intracavity-frequency-doubled c-cut Nd:GdVO4/KTP green laser with AO and GaAs

By simultaneously using both active and passive Q-switches in the same cavity, a diode-pumped doubly Q-switched intracavity-frequency-doubled c-cut Nd:GdVO4/KTP green laser with acoustic-optic (AO) modulator and GaAs semiconductor saturable absorber is realized. A comparison between c-cut and a-cut Nd:GdVO4 crystals shows that the doubly Q-switched c-cut Nd:GdVO4/KTP green laser can generate narrower pulse and higher peak power when the incident pump power is higher than 4.4 W. In addition, the doubly Q-switched c-cut Nd:GdVO4/KTP green laser can generate more symmetric and shorter pulse in comparison with singly AO- or GaAs-Q-switched laser. The coupled rate equations are used to simulate the process of these lasers.