Abstract

A method for controlling branching unimolecular reactions, developed in collaboration with M. Shapiro of the Weizmann Institute, which uses the coherence of weak lasers, is presented. It is shown that preselected chemical products may be obtained, in preference to others, by utilizing the interference between naturally occurring processes. Our specific application then entails the dissociation of a bound superposition state with control attained by manipulating the relative intensities and phases of coherent laser beams. Enhanced yields of chemical products of interest are shown to result. Similar control is attainable for the populations of individual product quantum states. Computational results on the I*II branching ratios in the photodissociation of CH³, I and FI are presented as examples. Proposals for experiments which demonstrate coherent control present a challenge to the laser community which is well worth accepting.

© 1986 Optical Society of America