Residual thermal effects in laser ablation of metals

Thermal energy remaining in Sn and Ti samples following femtosecond and nanosecond laser ablation is studied as a function of laser fluence and ambient gas pressure. When the laser fluence is above a certain threshold value, we find a significant enhancement in residual thermal energy deposition in air but a decrease in vacuum, and these effects occur for both femtosecond and nanosecond laser ablation. In contrast to the previous belief, our study demonstrates that femtosecond and nanosecond laser ablation share similar residual thermal effects.