Influence of intensity distribution of laser beam on the properties of nanoparticles obtained by laser ablation of solids in liquids

Control over the properties of nanoparticles obtained by laser ablation in liquids is experimentally demonstrated via modulation of the beam intensity profile on the target. Mask projection scheme was used with either a copper laser (wavelength of 510. 6 nm, pulse duration of 10ns) or with a Ti:sapphire laser (wavelength of 800 nm and pulse duration of 200 fs). Si and ZnSe were chosen as target materials. Obtained nanoparticles were characterized using Transmission Electron Microscopy (TEM), optical absorption spectroscopy and photoluminescence. It was shown that that size of Si nanoparticles depends on the spatial profile of the laser beam.