Abstract
The ability to rapidly change the focal plane of an optical system or rapidly change the intensity distribution in a given focal plane has many important applications in real-world systems ranging from high powered laser processing to detailed high-resolution microscopy. While accurate control over laser beam shape and focal position can enable precision control over the resulting materials properties in any laser processing application, few viable approaches exist that can provide the resolution and speed necessary for high throughput applications. In this presentation, we will discuss two examples of such control along with the implications for their applicability in industrial settings. In the first example, we will explore the use of ultrahigh-speed variable focus scanning for subtractive laser processing. Here we employ resonant scanning approaches to realize orders of magnitude increases in focal scanning speed and use this technology to gain significant improvements in the micro-machining efficiency of conventional systems and also open the door to high-efficiency laser processing on uneven topographies or within the bulk of a material. In the second example we look at the scaling of 3D metal printing using multiple beam laser powder bed fusion methods. Here we discuss how variation in laser intensity profile at the surface of the powder bed can drive or suppress melt pool instabilities during the printing process.
About the Speaker
Craig B. Arnold is the Vice Dean for Innovation and the Susan Dod Brown Professor of Mechanical and Aerospace Engineering at Princeton University. His research ranges from basic science to applied technology aimed at developing a deeper understanding of fundamental materials synthesis and processing with interests in, laser materials processing, novel material architectures, and advanced optics. He earned his PhD. in condensed-matter physics from Harvard University, and was an NRC post-doctoral fellow prior to joining the faculty at Princeton. He is the former director of the Princeton Materials Institute from 2015-2022. He has earned numerous accolades for his work in laser-based materials processing including the Knight of Laser Technology from the International Academy for Production Engineering, the Edison Patent Award for Technology transfer from the NJ R&D council, an R&D 100 award, the Laser Focus World-OSA technology innovation award, and the SPIE PRISM award for photonics innovation. Prof. Arnold is a fellow of OSA and SPIE.
Host: Professor Sam Tawfick
