Welcome to Fraser's Laser Lab
In his 1899 lectures Light Waves and Their Uses A. A. Michelson writes:
What would be the use of such extreme refinement in the science of measurement? Very briefly and in general terms the answer would be that in this direction the greater part of all future discovery must lie.What Michelson was advocating for was higher precision in scientific measurements. The answer to his call came over half a century later in 1960 with the invention of the laser. Since then lasers have become synonymous with precision and not just in the scientific community, fiber optic communication, consumer electronics and even the Internet are all built around the laser. The Fraser Group’s research aims to continue the laser revolution, using laser optics to advance science on two fronts:
Fundamental Physics: Ultrafast Dynamics and Quantum Optics
Research in ultrafast is truly cross-disciplinary since ultrafast processes are relevant in a wide range of fields, from semiconductor technology to bioprotein functionality. A key focus of our research is into the ultrafast of the ultrasmall. Man-made nanostructures provide a fascinating playground into the laws of quantum mechanics. Being small provides a complete new functionality and generates new applications all through novel ultrafast dynamics.
Short optical pulses are produced by compressing a submicrosecond duration pulse into 100 femtoseconds. That corresponds to an intensity increase greater than one million. Also, since the optical source is a laser, all the energy can be focused into a spot size comparable to the wavelength of light. The result is a beam with an intensity measured in TW/cm2. Such an intense beam seriously perturbs any matter it interacts with, moving our exploration into the nonlinear regime. We now have access to excited states of the system, can read out novel information about system symmetry, and can bridge transitions that normally would be forbidden. We can control the system in novel and often counter-intuitive ways, and read out information from the system that would normally remain hidden.
Applied Physics: Laser Material Processing
In-line coherent imaging (ICI) is an interferometric technique similar to optical coherence tomography, that measures the morphology evolution of the selective laser melting metal additive manufacturing process. ICI has a proven success record in monitoring and controlling laser welding, cutting and machining processes in real-time. A number of challenges still need to be overcome to adopt ICI to metal additive manufacturing.