High-peak-power passively Q-switched Nd:YAG/Cr 4+ :YAG composite laser with multiple-beam output

We report on the design, realization, and output performance of a diode-pumped high-peak-power passively Q-switched Nd:YAG/Cr4+:YAG composite medium monolithic laser with four-beam output. The energy of a laser pulse was higher than 3 mJ with duration of 0.9 ns. The proposed system has the ability to choose independently the focus of each beam. Such a laser device can be used for multipoint ignition of an automobile gasoline engine, but could also be of interest for ignition in space propulsion or in turbulent conditions specific to aeronautics.