A parametric study of sub-picosecond laser ablation of thin metal foils

Abstract With the properties of ultrashort pulse width and ultrahigh peak power, femtosecond lasers excel at processing materials whose thickness is less than 500 μm. Numerous experiments and theoretical analyses have testified to the fact that there are solid grounds for the future applications of femtosecond laser micromachining [1, 2]. However, with the high costs and complexity of these devices, it is the sub-picosecond laser that might be an alternative when it comes to micromachining of thin metal foils. Furthermore, investigating the sub-picosecond laser interactions with matter could provide a better understanding of the ablation mechanisms and experimental verification of existing models concerning the ultrashort pulse regime. We present research on sub-picosecond laser interaction with metal foils with a thickness of less than 250 μm under various laser pulse parameters. The research was conducted by two types of ultrafast lasers: a lab-designed sub-picosecond Yb:KYW laser (650 fs) and a commercial femtosecond Ti:S laser (35 fs). The results show how variables, such as pulse duration, energy, repetition rate, wavelength and irradiation time, affect the micromachining process.