Pulse shaping control of alignment dynamics in N2

Control on the alignment transients of impulsively aligned ensembles of N-2 molecules has been demonstrated by the use of laser pulses shaped by a spatial light modulator. An alignment experiment has been inserted in the feedback loop of an evolutionary algorithm that found optimum pulse shapes for a set of criteria. Optimum pulse shapes for the maximization of total alignment and for the control of certain aspects of the revival structures are given. The physical mechanisms responsible for the control are analysed with the help of single-parameter control schemes and numerical simulations, which allowed us to explore the low-temperature region. This approach sheds light on the role played by different control mechanisms for the alignment dynamics of a molecular ensemble. Copyright (C) 2006 John Wiley & Sons, Ltd.