Dynamic gratings induced by electrostrictive compression of critical microemulsions

We report on preliminary forced Rayleigh scattering experiments in a microemulsion system close to a critical point. It is shown for the first time that electrostriction induces sizable concentration gradients in a critical liquid mixture. The amplitude and the relaxation time of the induced gratings are found to increase divergently in the vicinity of the critical point, as expected from the known critical behaviors of the osmotic compressibility and of the correlation length of the concentration fluctuations.