Highly localized heat generation by femtosecond laser induced plasmon excitation in Ag nanowires

Photo-excitation of plasmons in nano-systems initially results in highly localized heating, but the final temperature distribution in irradiated nanostructures is almost uniform because heat diffusion equilibrates the overall temperature within ∼10−12 s. Here, we show that irradiation with femtosecond pulses enables visualization of the location of plasmonic heating because thermal effects such as plasmon-induced melting are frozen in at the initial location of energy deposition. Simulations show plasmonic heating is related to the orientation of the laser polarization and to the geometry of partially melted nanowires. This may provide a useful tool in joining, cutting, and reshaping nano-objects.