Dissymmetrization of micro-particle surface by laser-induced photochemical deposition

We investigate the surface dissymmetrization of micro-sized particles by using the photochemical reduction of chromate ions induced by a strongly focused CWAr+ laser to nucleate and grow deposits onto one hemisphere of silica beads dispersed in a chromate solution. Growth of dissymmetric coatings is performed at l = 514 nm with laser fluences varying from 1.3 to 10.1 kW/cm2. Rescaling of the measured deposit growth laws reduces to a single master behavior predicting the desired dissymmetry. The technique can be used to tailor micro-scale dissymmetric patterns by scanning with the beam.