INTERFERENCE CONTROL WITHOUT LASER COHERENCE - MOLECULAR PHOTODISSOCIATION

Control over channel-specific line shapes and branching ratios in photodissociation is shown to be achievable by irradiating a molecule with two intense cw lasers whose relative phase need not be well defined. Control results from quantum interference between nonlinear pathways induced by the intense fields, within which the relative laser phase cancels. The interference, and hence the product yields, can be manipulated by changing the relative frequencies and intensities of the two lasers. In this paper this theory of high field control is developed, and computations on the photodissociation of Na2 are presented. Control over product yields is shown to be extensive, even with inclusion of rotational states. For example, the branching ratio between the Na(Ss) +Na(3p) and Na(3s) +Na(4s) products can change by as much as a factor of 10 as the frequencies are tuned. © 1995 American Institute of Physics.