The acousto-optic Q-switched mode-locking Nd:YVO4 laser

Q-switched mode locking (QML) has been observed in acousto-optic Q-switched Nd:YVO4 laser that contained no mode-locking components. It was found that QML was easily realized in a long cavity and the modulation depth was observed to increase with increased cavity length. The maximum modulation depth was as high as 90%. This phenomenon is explained by the introduction of gain-related effect in the gain medium. The longitudinal modes at higher frequency, than the central frequency of the gain profile, experience positive guiding, which results in mode locking of these modes.