Ultrafast electron dynamics

We discuss the role of strongly driven electrons in the generation of attosecond laser pulses and in time-resolved experiments that can be performed using attosecond lasers. We show that the formation of attosecond laser pulses in high harmonic generation is an inevitable consequency of the physics of atoms in strong laser fields, combining the sub-cycle dependence of atomic ionization rates with controlled acceleration of the ionized electrons in the oscillatory field of the laser. Molecules undergoing dynamic alignment and/or enhanced ionization, and explosions of large rare gas clusters in an intense laser field are discussed in the context of attosecond electron dynamics.