Enhanced energy coupling in femtosecond laser-metal interactions at high intensities

It is commonly believed that thermal energy remaining in a target is negligible following femtosecond laser ablation. In contrast to this belief, however, we observe a significant enhancement in thermal energy retained in a target following single-pulse ablation. Ambient gas plasmas produced near the sample surface are shown to play a key role in the enhanced residual energy coupling. Our study reveals, for the first time, an enhanced energy coupling in single-shot high-intensity femtosecond laser-metal interactions and provides new guidelines for a broad range of technological applications.