Abstract. We present a self-consistent theory and analytical results for the three-photon-one-photon coherent control of ionization in an optically dense autoionizing medium. We show that for an optically thick medium, over a short scaled propagation distance, the phase and amplitude of the harmonic field settle to values that are fully determined by the atomic and fundamental field parameters and are completely independent of the initial relative phase between the two fields, thus preventing efficient phase control of the autoionization and its products. Control of the autoionization and the branching ratio of its products is still feasible, however, through the variation of the detuning of the fundamental field from the atomic transition resonance.

Print publication: Issue 9 (14 May 2001)
Received 9 September 2000, in final form 12 February 2001