At the speed limit and at the boundaries of the measurable

Venue: Theatre A, Elisabeth Murdoch Building

Presenters: Professor Ursula Keller

Whether at her coffee machine in the morning, on her way to work in the car or at her computer in the office – Ursula Keller keeps seeing items in her daily life that were produced with the aid of laser processing.

Nowadays, these powerful light sources are used in many places to shape surfaces or cut materials to the right size, and Keller has had a major hand in this. As a professor of experimental physics over 20 years ago, she developed SESAM technology that enables powerful laser light to be focused into ultra-short pulses. And it is these same, short, high-energy pulses that make it possible to process materials in a gentle, precise way. The further development of the lasers, however, is only part of Ursula Keller’s work. For her group also uses them to study ultrafast processes. Her cutting edge laser technology enabled for example the world’s most accurate clocks – the optical clock and the attoclock.

With the optical clock we can measure a few centimeters of height differences as predicted by Einstein’s general relativity theory or can help to discover new planets. With the attoclock we can study the tunnel effect, a quantum-mechanical phenomenon that was previously impossible to investigate experimentally because it takes place at an inconceivable speed. In concrete terms, it concerns how quickly an electron excited with light can be transported away from an atom which can take place in the space of attoseconds, i.e. a billionth of a billionth of a second.

This talk will give a general introduction on how we can access a new regime of measurements in our “ultrafast world” which has a big impact on our everyday lives. For without these extremely speedy processes there would be no photosynthesis, no breathing and no eyesight.

from
https://events.unimelb.edu.au/events/6498-at-the-speed-limit-and-at-the-boundaries-of-the