Pulsed-Laser Generation of Nanostructures

Abstract

We discussed two main approaches for generation of nanometer-scale structures using pulsed lasers. In the first, a bulk material is ablated in vacuum, gas or liquid and consequent re-solidification of the evaporated material in clusters generate the desired nanoparticles. While one can play with various experimental parameters (laser powers, type of liquids, background gas etc.) to control particle sizes, there is always a relatively broad distribution of particle sizes. Nevertheless, particles with sizes down to few nanometers are achievable. In the second approach, fs lasers are used to pattern material surfaces. This process is more controlled in the sense that the desired geometries are generated by scanning of the sample. On the other hand, best achievable resolutions are worse as compared to the former approach. Resolutions better than 100 nm over large surfaces is very difficult. Finally, special beam shaping methods forms an interesting frontier in pushing forward the fs laser nanomachining methods towards broader practical uses.