Dynamic ultramicroscopy of laser-induced flows in colloidal solutions of plasmon-resonance particles

A method is proposed for visualisation of the velocity fields of colloidal plasmon-resonance nanoparticles moving in a laser beam. The method uses the particle image velocimetry for processing ultramicroscopic images. Particles in a thick layer of colloidal solution are illuminated by a slit laser ultramicroscopic source with a large numerical aperture providing a high contrast of particle images and visualisation of the transverse velocity distribution in laser-induced flows with a high spatial resolution. (special issue devoted to application of laser technologies in biophotonics and biomedical studies)