Abstract

Tunneling of a particle through a barrier is one of the most fundamental and ubiquitous quantum processes. When induced by an intense laser field, electron tunneling from atoms and molecules initiates a broad range of processes that evolve on the attosecond time-scale^1,2. As the liberated electron is driven by the laser field, it can return to the parent ion and recombine to the initial (ground) state, releasing its energy in an attosecond burst of light. This process, known as High Harmonic Generation (HHG) provides an excellent spatio-temporal filter for the electron motion. The angstrom-scale spatial resolution is determined by the size of the atomic ground state to which the electron must recombine. The attosecond temporal resolution arises from the mapping between the photon energy (harmonic order) and the return time of the corresponding electron trajectory.

© 2013 IEEE