Influence of MHz bursts on the ablation efficiency of fused silica

• Main Authors: Esen, C. (Author), Hellmann, R. (Author), Schwarz, S. (Author), Yang, Y. (Author)
• Format: Article
• Language: English
• Published: Laser Institute of America 2023
• Subjects: Ablation; Ablation efficiency; Ablation thresholds; Burst-mode; Efficiency; Efficiency increase; femtosecond laser; Femtosecond lasers; Fluences; fused silica; Fused silica; Maximum Efficiency; MHz burst; Micro milling; Micromachining; micromilling; Milling (machining); Repetition frequency; Subpulse; Surface roughness
• Online Access: View Fulltext in Publisher

 We report on micromilling of fused silica using a 1030 nm femtosecond laser with an intraburst repetition frequency of 40 MHz. Milling of cavities reveals a monotonously increasing ablation efficiency with increasing subpulse number, while the ablation threshold of each subpulse decreases. These results prove that MHz bursts benefit the milling of fused silica. In comparison to the non-burst mode, the maximum efficiency increases about 1.6 times by using a 10 subpulse burst. In addition, bursts cause coarse ablated surfaces, whereas low subpulse numbers in conjunction with increasing fluences lead to a reduction of the surface roughness. A subpulse number of 2 keeps the roughness at the same level as for non-burst at high fluences while enhancing the ablation efficiency about 0.08 mm 3 /min/W. © 2023 Author(s).