Picosecond dual-pulse laser ablation of fused silica

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2022-05, Vol.128 (5), Article 450
• Main Authors: Wu, Ping-Han, Young, Hong-Tsu, Li, Kuan-Ming
• Format: Article
• Language: English
• Subjects: Ablation; Applied physics; Characterization and Evaluation of Materials; Condensed Matter Physics; Excitons; Free electrons; Fused silica; Laser ablation; Machines; Manufacturing; Material absorption; Materials science; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Shielding; Surfaces and Interfaces; Thin Films; Thresholds; Yield point
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-022-05575-0

This study discussed the ablation thresholds of picosecond laser dual pulses in fused silica with different temporal separations. The results indicate that the lowest damage threshold of the dual-pulse ablation is at a temporal separation of 100 ps, which is only half of the threshold of the conventional pulse ablation. Furthermore, the energy ratios of two sub-pulses were optimized to minimize the thresholds. Regarding the underlying physical mechanisms, this study found that the first sub-pulses initially excited the electrons of the fused silica, and subsequently induced free-electron shielding and self-trapped exciton seed generation at different temporal separations. This either decreased or increased the material absorption of the second sub-pulses, resulting in changes of the ablation threshold of the fused silica. The results of the picosecond dual-pulse ablation could provide further understanding into the interaction mechanisms of dual pulses to transparent materials.