Single Nanoparticles and Nanoplasmas in Femtosecond Laser Fields

We combine an aerodynamic lens with a velocity-map-imaging spectrometer to make the first measurements of ultrafast dynamics in individual nanoplasmas. By using two laser pulses (800 and 400 nm) delayed by several picoseconds, we find that we can generate and control shock wave propagation in nanoplasmas, confirming a decade of theoretical predictions. Additionally, we observe pronounced asymmetries in the photoion angular distributions resulting from nanoparticles of different structure and composition, demonstrating the ability to observe nanoscale light absorption at laser intensities near the damage threshold.