Colloquium: Oct 26, 2016
F. Ömer İlday*
Ablation-cooled laser cutting: From science fiction to science (twice)
|October 26, 2016 Wednesday||15:40||EE 01|
ABSTRACT — Since its invention, the laser has been idealized as the perfect cutting tool that can work with ease and surgical precision on any material. But the reality has turned out to be different. High-power lasers can indeed cut through thick steel, but very slowly, and only by enormously heating the entire piece. Variations on the technique have been developed, but they all suffer either from damage to the target material, with biological tissue being particularly sensitive, or can only cut extremely slowly, while requiring complex and expensive laser technology. We have recently invented a technique that circumvents all of these pitfalls, and as a result laser cutting is now much closer to its idealized image (Ilday, et al., Nature, 2016). In our approach, laser pulses are sent so quickly one after another that there is no time for heat to diffuse away from the processing region, keeping the rest of the target material cool and without damage. By doing so, we have reduced the required laser pulse energies by 1000 times, while enormously simplifying the laser technology, increasing efficiency by more than 10 times and achieved record speeds in cutting biological tissue. The implications for industrial and medical technologies are extremely exciting. At the time of conception of this idea, the laser technology we needed to demonstrate it did not exist. We developed it ourselves over the course of several years before making the decisive experiments that proved ablation cooling. The fundamental science that motivated this particular solution originates from our extensive efforts to exploit nonlinear and stochastic dynamics via judicious use of nonlinear feedback mechanisms in numerous physical systems. This talk will briefly touch on other accomplishments of this approach, in addition to explaining how the speaker’s love of science fiction has influenced this study.
*Bilkent University, Department of Physics & Department of Electrical and Electronics Engineering
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