Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

Laser Micro-machining

Prof. James Fraser
Department of Physics, Queen's University

Friday, January 13, 2012
1:30 PM @ Stirling A

Abstract:

Though tightly focussed laser beams can cut and weld with high transverse precision, without Lucas, lightsabre technology, depth control remains a problem. This is particularly problematic in cases where laser material processing is highly stochastic due to complicated light-matter interactions, sample morphology changes (including melt flow) and even material heterogeneity.

We have adapted a medical imaging modality (optical coherence tomography) to achieve high-speed axial imaging during laser processing (rates > 300 kHz). Inline coherent imaging allows direct measure of laser processing dynamics that were previously not observed, recording "movies" of the material change.

We have also exploited this in situ imaging technique to close the feedback loop to achieve what was recently described in the literature as "...the so-far elusive goal of the online control of laser micro-machining," namely fully automatic computer control of laser drilling.

Refreshments will be available before the talk.