Basic studies on ultrafast laser ablation processes are important for expanding their utility. In particular, understanding the ablated morphology in relation to the incident pulse is critical for micromachining, and an important benchmark for simulations. However, current morphological analyses rely on vast simplifications of experimental conditions, such as a singular fluence value to reduce a unique beam profile, or the maximum crater depth or diameter to describe the ablated morphology. Here, we develop a morphology analysis method in which we take the full two-dimensional information of both the input beam profile and the ablated morphology, and spatially correlate the two without data reduction. We show, using sapphire as a benchmark material, that this serves as a robust way to extract well-studied values and dependencies, such as the ablation threshold, and also as a way to probe the spatial independence of the process. We anticipate that our findings will modernize current study techniques to meet the demand for increased, high-quality data such as that required for artificial intelligence-based analysis.

See below for more information.

• Aritcle URL : https://www.nature.com/articles/s43246-021-00138-x
• Nakatsuji-Sakai Lab. : http://www.gono.t.u-tokyo.ac.jp/e_index.html