A highly stable 30 W average power mode-locked Nd:YAG laser

Mode locking of a CW pumped Nd:YAG laser operating in the TEM01or donut mode using an intracavity acoustooptic AM modulator is described. Mode-locking investigations to date have concentrated on obtaining as short pulses as possible at the expense of average and peak laser output power. We describe a mode-locked system for field use having an average output of 30 W, with pulses recurring at a 100 MHz rate and having a peak power in excess of 0.5 kW. Detector limited pulses of 0.6 ns duration were recorded and the mode locking was stable for several hours requiring no feedback loop or fine adjustment.