Q-switched mode locking with acousto-optic modulator in a diode-pumped Nd:YVO4 laser.

The Q-Switched Mode Locking (QML) regime provides the generation of relatively high peak power picosecond pulses train with energies of a few muJ each in a simple resonator. The fully modulated efficient QML regime was demonstrated in the diode-pumped Nd:YVO4 laser. The acousto-optic cell playing a double role of Q-switch and Mode Locker was located near flat output coupler. The two folding mirrors were mounted on the translation stages for matching the resonance frequency of the cavity to the radio frequency of acousto-optic modulator. The QML pulses with envelope durations of 100-150 ns and near 100% modulation depth were observed for wide range of pump powers and repetition rates. Up to 3 W of output average power, 100 muJ of the envelope energy, having approximately 5-8 mode-locked pulses were achieved.