Liquid stone all seminars
Date: Monday, November 19, 2018 Time: 3:00-4:00 pm Place: 1-123
Abstract: Since the discovery of ultrafast lasers in the 90’s, pulsed lasers have been used to excite and detect ultrasound with corresponding frequencies up to the THz range. At this ultimate frequency range, the ultrasonic wavelength is on the order of a couple of nanometers only, that makes them suitable for the mechanical probing of nano-objects of similar dimensions. This technique perfectly fits the needs for non-contact, non-invavise, non-destructive mechanical probing of solid or liquid samples.
Depending on the laser peak energy used in the experiment, the ultrasound pressure can even be tuned to many GPa. In this high energy situation, the intense ultrasound wave becomes a shock wave that can be used to probe the nonlinear mechanical characteristics of the sample.
In the up-coming seminar, I will review the latest results which we have obtained dealing with ultrafast and/or ultra-intense laser ultrasounds. I will describe the richness of laser acoustics for the investigation of confined liquids, for the investigation of fundamental processes of laser-matter interactions, for the investigation of weakly nonlinear mechanical properties of solids or liquids and for the investigation of strongly nonlinear properties of materials under laser-induced shock loading as well.