Effect of Surface Plasma on Nanosecond Laser Ablation

For the first time, the effect of target surface plasma on nanosecond laser ablation is studied. Surface plasma was generated by a high-power cw fiber laser beam incident on an iron target. A comparison of laser ablation by nanosecond Nd:YAG laser pulses (1064 nm, 5 ns) was performed upon exposure to the cw laser and during its short-term (5 ms) turn off. It was found that the emission intensity twofold increases in the presence of surface plasma. The temperature and electron density of the laser plume induced by the nanosecond laser also increased.