Theoretical and experimental study of a laser-diode-pumped actively Q-switched intracavity-frequency-doubling Nd:YVO4/KTP laser with acousto-optic modulator

By considering the Guassian spatial distribution of the intracavity photon density and the longitudinal distribution of the photon density along the cavity axis as well as the influence of turnoff time of the acoustic-optic Q-switch, the coupled rate equations of actively Q-switched intracavity frequency-doubling Nd:YVO4/KTP laser with acoustic-optic modulator are given. These coupled rate equations are solved numerically, and the dependences of pulse width, single-pulse energy and peak power on incident pump power are obtained for the generated-green-laser pulses. In the experiment, a laser-diode end-pumped actively Q-switched Nd:YVO4/KTP laser with acoustic-optic-modulator is realized and the experimental results agree with the numerical solutions.