Phase separation and droplet nucleation induced by an optical piston

Abstract
We propose to use laser-induced concentration variations due to electrostrictive or thermodiffusive coupling in order to drive a phase separation in a liquid mixture. The properties of such a composition quench, analyzed in a microemulsion in the thermodiffusive case, are reported. Droplets of the minority phase are nucleated and trapped in the laser beam, and their dynamics is described. This experiment allows one to analyze nucleation in an original wetting-free one-dimensional geometry.