Time-resolved emission and scattering imaging are employed to analyze the ablation mechanisms of silver thin films induced by femtosecond laser irradiation of Gaussian intensity profile under different laser fluences and gas background pressures. At fluences near the ablation threshold, nanoparticles (NPs) of 40 nm-100 nm in size are ejected in the vertical direction from the target sample. The average ejection speed of these NPs increases with the laser fluence and also as the background gas pressure drops from ambient atmospheric to $10 À5 Torr. At higher fluences, a plume is formed at the center of the laser beam and NPs are released in oblique trajectories from the peripheral area of the laser-irradiated spot.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.