In this work, we investigate single-pulse laser ablation of bulk stainless steel (AISI304), aluminium (Al) and copper (Cu) and its dependence on the pulse duration. We measured the reflectivity, ablation thresholds and volumes under the variation of pulse duration and fluence. The known drop of efficiency with increasing pulse duration is confirmed for single-pulse ablation in all three metals. We attribute the efficiency drop to a weakened photomechanically driven ablation process and a stronger contribution of photothermal phase explosion. The highest energetic efficiency and precision is achieved for pulse durations below the mechanical expansion time of 3-5 ps, where the stress confinement condition is fulfilled.

中文翻译：

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不锈钢，铝，铜的超短单脉冲激光烧蚀及其与脉冲持续时间的关系

在这项工作中，我们研究了散装不锈钢（AISI304），铝（Al）和铜（Cu）的单脉冲激光烧蚀及其对脉冲持续时间的依赖性。我们测量了脉冲持续时间和注量变化下的反射率，烧蚀阈值和体积。对于所有三种金属中的单脉冲消融，都证实了已知的效率随脉冲持续时间的增加而下降。我们将效率下降归因于光机械驱动的烧蚀过程减弱以及光热相爆炸的较强贡献。在满足应力限制条件的3-5 ps的机械膨胀时间以下的脉冲持续时间内，可获得最高的能量效率和精度。