Abstract

The effect of quantum interferences occurring in the continuum of ionization of atoms has received a revival of interest since the proposal by Harris of lasing without population inversion.^[1] Laser-induced autoionization of atoms is characterized by two interfering ionization channels (photoionization and autoionization) leading, in the weak-field limit, to the Fano absorption profile^[2] and, in the strong-field regime, to other coherent phenomena such as the trapping of atomic population, the confluence of coherences in the electron spectrum and the enhancement of the photon yield.

© 1992 IQEC