The School of Mechanical and Materials Engineering Seminar Series, “High energy lasers for material development and processing” Presented by Dr. Javier E. Garay

About the event

High energy lasers for material development and processing

Presented by

Dr. Javier E. Garay, Professor, Department of Mechanical and Aerospace Engineering and Materials Science Engineering, University of California, San Diego

Abstract:

Tunable ultrafast lasers can impart controllable yet extreme temperatures and pressures producing combinations of defects (point, line and planar along with mobile and/or trapped electrons/holes) that in concert behave effectively as ‘phases.’ In turn these defects and phases affect thermal and optical properties. For example, point defects (vacancies and impurities) and grain boundaries can scatter phonons/photons, modify refractive indices and linear/non-linear absorption. I will present our ongoing work to understand laser-material interaction at various intensity regimes, using lab scale to facility scale laser facilities.  We will also discuss a recently developed ceramic laser welding procedure. It relies on focusing light on interfaces to ensure an optical interaction volume to stimulate linear/nonlinear absorption processes, causing localized melting rather than ablation. The key is the interplay between linear and nonlinear optical properties and laser energy–material coupling. We show that tuning of the grain sizes and defect concentrations is important for successful laser joining.

Bio:

Javier E. Garay is a professor in the department of Mechanical and Aerospace Engineering and the Materials Science and Engineering Program at the Jacobs School of Engineering at the University of California, San Diego (UCSD). He is also the Associate Dean for Research in the Jacobs School. He received a B.S. in Mechanical Engineering, an M.S. and Ph.D in Materials Science and Engineering all from the University of California, Davis. His research focuses on materials processing, property measurements and the integration of materials in devices. The application spaces are in optical devices, magnetic devices, thermal energy storage/ management. He is also particularly interested in understanding the role of the length scale of nano-/ micro-structural features on light, heat and magnetism. Prof. Garay is on the editorial advisory board for Applied Physics Letters and is a Deputy Editor for AIP Advances.