Nonlinear excitation of capillary waves by the Marangoni motion induced with a modulated laser beam

Abstract

We have studied the amplitude and phase relationships of capillary waves produced by modulated laser light on the surface of strongly absorbing liquids. For increasing laser fluences a strong nonlinear behavior is observed. This is connected with the convective motion of the liquid created by surface tension gradients known as the Marangoni motion. The abrupt changes in both the capillary wave amplitude and the phase are found to be due to an autoblocking effect of the heat flux from the region of the laser absorption as the result of the development of a closed circulating flow of the liquid.