High power diode-pumped passively Q-switched and mode-locking Nd:GdVO4 laser at 912Â nm

A high power diode-end-pumped passively Q-switched and mode-locking (QML) Nd:GdVO4 laser at 912 nm was demonstrated for the first time, to the best of our knowledge. A Z-type laser cavity with Cr4+:YAG crystals as the intracavity saturable absorber were employed in the experiments. Influence of the initial transmission (TU) of the saturable absorber on the QML laser performance was investigated. Using the TU = 95% Cr4+:YAG, as much as an average output power of 2.0 W pulsed 912 nm laser was produced at an absorbed pump power of 25.0 W, then the repetition rates of the Q-switched envelope and the mode-locking pulse were ~ 224 kHz and ~ 160 MHz, respectively. Whereas the maximum output power was reduced to 1.3 W using the TU = 90% Cr4+:YAG, we obtained a 100% modulation depth for the mode-locking pulses inside the Q-switched envelope.