A compact subnanosecond high power Nd:YAG laser system

In this paper, a high power Nd:YAG laser system is described, which consists of an actively-passively mode-locked Nd:YAG laser oscillator with variable subnanosecond pulsewidths (200 ps to 1 ns), a Pockels-cell shutter and a coaxial four-pass Nd:YAG amplifier. With the oscillator operating in the colliding pulse regime, and a BDN dye film as the saturable absorber, and an acousto-optic modulator as the active modelocker, we have achieved a shot-to-shot stability of the pulse-train amplitude < ±4%. For a 0.1 mJ, 200 ps laser pulse, we obtained four-pass amplification of 7 × 10² with a pump energy of 106 J.