Synthetic Schlieren Measurements of Laser-Actuated Surface Waves

When an infrared laser is pulsed on a fluid interface, the absorption of light can lead to sudden changes temperature at the interface leading to a localized change in the surface tension of the fluid. The resulting surface tension gradient leads to the emergence of thermocapillary waves, which propagate across the interface. In this talk, we present preliminary experimental characterization of the surface topography of these waves using the synthetic schlieren technique. We compare our results to our earlier measurements of laser-actuated waves generated when a laser is pulsed on a fluid interface subjected to parametric forcing by vertical oscillation of its container.