title: Pulse-train control of photofragmentation at constant field energy.
abstract: We consider a phaselocked two-pulse sequence applied to photofragmentation in the weak-field limit. The two pulses are not overlapping in time, i.e., the energy of the pulse-train is constant for all time delays. It is shown that the relative yield of excited Br (*) in the nonadiabatic process: I + Br* ← IBr → I + Br, changes as a function of time delay when the two excited wave packets interfere. The underlying mechanisms are analyzed and the change in the branching ratio as a function of time delay is only a reflection of a changing frequency distribution of the pulse train; the branching ratio does not depend on the detailed pulse shape.
authors.affiliation: Indian Institute of Science Education and Research Kolkata, Mohanpur 741 252, India.
authors.forename: Ashwani K
authors.initials: AK
authors.lastname: Tiwari
authors.affiliation: Department of Chemistry, Building 207, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Niels E
authors.initials: NE
authors.lastname: Henriksen