A Novel Laser Micro-machining Technique using Synthesized Femtosecond Pulse Bursts

本研究的目的是研究新型飞秒激光加工技术，用于制造各种微结构和部件。该方法是优化所有激光操作参数;特别是通过合成飞秒脉冲群（1飞秒= 1/1，000，000，000，000，000秒）来优化激光脉冲的时间形状，这在商业激光加工系统中不可用。在这些飞秒脉冲群中，每个激光脉冲的能量将被单独控制，脉冲到脉冲的分离时间将从飞秒调整到纳秒。这将允许在几乎任何材料中加工高质量的微结构。飞秒激光与物质相互作用过程中的基本物理现象将被研究，以帮助脉冲群的设计。这项工作如果成功，将大大推动激光加工技术的发展。 尽管使用飞秒脉冲激光器进行微加工具有许多优点，但由于激光照射的熔体喷射和熔体液滴的再沉积，通常无法获得清洁和理想的结构。这项工作旨在解决与激光微加工相关的常见问题，以实现更清洁和更高精度的加工结果。这项工作的成功将影响许多行业，包括航空航天，汽车，微电子和生物技术，其中激光微加工已经得到广泛应用。该项目还将有助于下一代高科技劳动力的教育。它将为学生提供跨学科的培训。这项研究的结果将被纳入本科和研究生课程，并传播到学术和工业激光加工社区。

The objective of this research is to investigate novel femtosecond laser machining techniques for manufacturing a variety of microstructures and components. The approach is to optimize all laser operation parameters; in particular, the temporal shape of laser pulses by synthesizing femtosecond pulse bursts (1 femtosecond = 1/1,000,000,000,000,000 second), which are not available in commercial laser machining systems. In these femtosecond pulse bursts, the energy of each laser pulse will be individually controlled, and the pulse-to-pulse separation time will be adjusted from femtoseconds to nanoseconds. This will allow high quality microstructures to be machined in almost any materials. Fundamental physical phenomena during femtosecond laser-matter interaction will be investigated to assist the design of the pulse bursts. This work, if successful, will greatly advance the laser machining technology. Despite many advantages of using femtosecond pulse lasers for micro-machining, clean and desirable structures are often not obtained due to melt ejection by laser irradiation and re-deposition of melt droplets. This work is aimed at solving common problems associated with laser micro-machining to achieve cleaner and higher precision machining results. The success of this work will impact many industries, including aerospace, automobile, microelectronics, and biotechnology where laser micro-machining is already widely used. The project will also contribute to education of the next generation high tech workforce. It will provide the students involved with cross-disciplinary trainings. The results of this research will be integrated into undergraduate and graduate curricula and disseminated to both academic and industrial laser processing communities.