MULTIPRODUCT COHERENT CONTROL OF PHOTODISSOCIATION VIA 2-PHOTON VERSUS 2-PHOTON INTERFERENCE

We show that the branching ratios into two or three channel photodissociation products can be controlled by a novel resonant two-photon vs two-photon coherent control scenario. The method allows for control even when the initial molecular system is in a mixed state, e.g., in thermal equilibrium, a significant advance for controlling reactions. Essential to the technique is the phase locking between different frequencies which results in cancellation of incoherences due to laser phase jumps. Reduction of uncontrolled background contributions also obtains. The scenario is demonstrated computationally on Na2 photodissociation, where a wide range of control is achieved over branching into two product channels [Na (3s) + Na (4s) vs Na (3s) + Na (3p)] at lower energies and over three product channels at energies above the Na (3s) + Na (3d) threshold.