Laser control of molecular processes.

TLDR: Theoretical and computational advances, supported by preliminary experimental results, now clearly indicate that efficient control over molecular processes is possible.

Abstract: The last 20 years have seen enormous strides in our understanding of the detailed dynamics of elementary chemical reactions ( 1 -3). With this understanding well in hand, attention has turned to controlling, rather than passively observing, molecular collision processes. Theoretical and computational advances, supported by preliminary experimental results, now clearly indicate that efficient control over molecular processes is possible. We review these advances in detail below. The primary goal of practical chemistry is to produce desired molecular products in substantial yield. For decades, enhanced productivity was attained by thermodynamic techniques, e.g. variations in pressure and temperature. Recently, efforts have been directed toward using properties of lasers to enhance desired product yield selectively. Initial efforts attempted to utilize high laser power (4-Sc) to manipulate molecules; control was based on introducing into the system Hamiltonian, laser­ molecule coupling terms of comparable size to interatomic potentials. A second thrust, "mode-selective excitation," emphasized selective excitation of particular bonds, which encourage reaction toward one channel. These