  We discuss the dynamics of the two-photon resonant ionization of helium
involving two autoionizing states in the presence of two-color laser fields.
The first source is tuned around the transition from the ground state to the
2s2p 1Po autoionizing state, and the second couples the state 2s2p 1Po to the
2p2 1S autoionizing state. The laser coupling between the doubly excited states
is shown to lead to modifications of the Beutler-Fano profile and the
appearance of an Autler-Townes doublet. This double resonance effect between
autoionizing states can be observed at moderate laser intensities easily
attainable by currently operated sources.

Atomic Physics