A molecular-scale photocathode - using a molecule's own electrons to image itself

Free electrons in intense laser fields can oscillate with relativistic velocities. By choosing the optical phase at which an electron is detached from an atom or molecule, the electron can re-collide with its parent ion with energies ranging from eV to MeV. Because the electron originates from its target, the probability of re-collision is high, leading to equivalent current densities exceeding 1010 A/cm2. We characterize the attosecond duration of these current pulses, and show how it may be possible to time-resolve nuclear processes.