Laser-induced giant deformation of a liquid-liquid interface

Summary form only given. If the interaction between a laser wave and a solid micrometer-sized dielectric body has aroused a great deal of interest during the last decades, much little attention has been directed to electrostrictive distortions of soft interfaces despite important applications in biophysics (cell deformation) and propagation through droplet suspensions (fog). Indeed, in classical situations, high intensities are generally needed to deform interfaces due to the large involved surface tension. As a consequence, (i) secondary disturbing thermal couplings may appear and destroy the expected behavior and (ii) when observed, deformations are always weak [2]. To overcome these difficulties, we performed the experiment in a phase-separated microemulsion because surface tension in micellar systems is intrinsically very low. Then, the interface becomes extremely soft and typical beam powers of a few hundreds of mW offer the opportunity to induce huge stable deformations for testing the theory of the electromagnetic stress tensor. We also observe a needle formation (secondary stage of the interface instability) resulting from the coupling with the beam propagation.