High power diode-pumped passively Q-switched and mode-locking Nd:GdVO 4 laser at 912 nm

Abstract

A high power diode-end-pumped passively Q-switched and mode-locking (QML) Nd:GdVO 4 laser at 912 nm was demonstrated for the first time, to the best of our knowledge. A Z-type laser cavity with Cr 4+:YAG crystals as the intracavity saturable absorber were employed in the experiments. Influence of the initial transmission ( T U) of the saturable absorber on the QML laser performance was investigated. Using the T U = 95% Cr 4+: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 T U = 90% Cr 4+:YAG, we obtained a 100% modulation depth for the mode-locking pulses inside the Q-switched envelope.