STIMULATED-EMISSION PROCESSES AND STRONG-FIELD EFFECTS IN ULTRASHORT-PULSE EXCITATION OF A PREDISSOCIATIVE MOLECULE

We study the interaction of a diatomic molecule with two ultrashort an d strong laser pulses. The first pulse prepares a wave packet in a dis sociative electronic state which is coupled non-adiabatically to the b ound electronic ground state. The conditions under which it is possibl e to stimulate parts of the wave packet back down to the ground state, a process which competes with excitation to a higher electronic state , are investigated. The results show to which extent it is possible to selectively transfer population between bound and dissociative states and thus influence the yield of a simple chemical reaction. (C) 1997 Elsevier Science B.V.