Evolution of nanosecond laser-induced phase explosion based on a high-speed continuous imaging system

A high-speed continuous imaging system is established based on the principle of multiwavelength shadow imaging with a 15-ns exposure time and 1-ns frame interval. Furthermore, the spatiotemporal evolution of phase explosion products induced by Nd: YAG nanosecond laser ablation of aluminum was observed. The results show that, at the laser flux of 1.34 J/cm(2), only shockwave is caused by strong evaporation; above the laser flux of 2.05 J/cm(2), the shadow image shows significant explosive particles jet. When the injected laser flux reaches 3.32 J/cm(2), the plasma explosion is accompanied by the phase explosion. Moreover, at a laser flux between 1.34 and 2.05 J/cm(2) the velocity of shockwave fronts surges owing to the phase explosion. At a laser flux of 2.86-3.32 J/cm(2), the wavefront velocity resurges under the effects of phase explosion and plasma explosion.