Dynamics of Multiple Ionization in Strong Laser Fields

We will review recent experiments on multiple ionization of atoms by femtosecond laser pulses in the $10^{14}-10^{15} W/cm^2 $ regime. The dynamics of the multiple ionization process via rescattering is unravelled on a subfemtosecond time scale. This is achieved by imaging the momenta of electrons and ions in coincidence using the COLTRIMS technique.