Above-threshold ionization and the quantum mechanics of wiggling electrons.

Intense laser fields can dramatically alter the behavior of free and bound electrons. Some effects, such as the scattering of electrons by light, are due to classical wiggling in response to the periodic driving force. Others, such as above-threshold ionization of atoms, depend on the wave nature of the electron, and require quantum mechanics for a complete explanation. This paper reviews some recent experiments that have contributed to our understanding of the physics of light-matter interactions in this new regime.