Effects of laser polarization and linear surface features on nanoparticle synthesis during laser ablation in liquids

We elucidate non-isotropic interactions present during laser ablation of ridged surface features under linearly-polarized light and their effect on nanoparticle synthesis via the laser ablation in liquid method. A relationship between the relative polarization/ridge orientation and ablation processes was established by measuring cavitation bubble kinetics, examining the morphology of the ablated surface, and evaluating nanoparticle size distribution. Anisotropic behavior was observed, and this is attributed to selective heating of linear surface structures as confirmed with rigorous coupled-wave analysis. When the incident electric field is aligned parallel to the linear ridges on the target surface, the resulting nanoparticle distributions are much more monodisperse. This phenomenon has a strong influence in the polydispersity and batch-to-batch reproducibility in laser ablation in liquid.