Femtosecond laser-induced line structuring on mold stainless steel STAVAX with various scanning speeds and two polarization configurations

摘要

A femtosecond laser has been used to produce spatially confined micromachining on mold stainless steel STAVAX. We investigated femtosecond laser-induced line structuring on mold stainless steel STAVAX using the laser scanning mode with various scanning speeds, various fluences and two polarization configurations. The damage threshold fluence of single pulse irradiation (Fth) was measured to be about 80 mJ/cm2. The damage threshold fluence of the scanning mode was approximately identical (0.75 Fth∼1.25 Fth) to that of the single pulse irradiation. However, a fluence of 2.50 Fth was necessary to induce continuous line structures for high scanning speeds and a fluence of 1.25 Fth was required to induce continuous line structures for low scanning speeds. The width of laser-machined lines increased with the irradiation fluence and decreased with the scanning speed regardless of the polarization configuration. The formation of laser-induced periodic structures (termed “ripple”) was examined using various laser parameters. It was clear that the formation of the ripple was governed by the irradiation fluence and the scanning speed of the beam. We were able to produce nano-scale structures in large areas by employing multiple line irradiations with the laser beam.