All-optical alignment and orientation of the molecular angular momentum
Using dressed states created by laser radiation to align and orient the molecular angular momentum
Preparing gas-phase molecules with a pre-selected orientation is one of the main goals in chemical reaction dynamics. The ability to pre-select well-defined initial reactant quantum states eliminates ensemble averaging which greatly complicates the interpretation of dynamics effects in chemical reactions. In addition, initial state selectivity enhances the viability of quantum control schemes which seek to direct the course of chemical reactions.
Similarly, all-optical control of molecular orientation and alignment on surfaces may turn out in the future to be a very attractive means for providing insights into mechanisms of chemical reactions on surfaces as well as helping advance the molecular-electronics approach to device fabrication. The current efforts in the former area include surface aligned photochemistry, where the crystalline surface structures are used to align and position chemical reagents prior to reaction.
Furthermore, alignment of a molecule along a laser propagation direction is crucial for Coulomb explosion type molecular imaging.