Ionization and Fragmentation ofC60via Multiphoton-Multiplasmon Excitation

Abstract

We study the intensity dependence of ionization and fragmentation of buckminsterfullerene ( ${\mathrm{C}}_{60}$) in strong laser fields. Our data provide strong evidence that at intensities $\lesssim {10}^{14}\mathrm{W}/{\mathrm{cm}}^2$ these processes occur predominantly via multiphoton excitation of the 20 eV plasmon resonance of ${\mathrm{C}}_{60}$. At least two plasmons have to be created to initiate fragmentation or multiple ionization.