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.
