Abstract:

Since the invention of the laser, chemists have dreamed of designing specially tailored laser pulses to control the outcome of chemical reactions.  This talk will start with a brief overview of the field, introducing the theoretical concepts and the current experimental status.  Then two recent developments in our group will be described.  The first is a method based for complete reconstruction of the excited state wave packet.  Significantly, the method applies to polyatomics as well as diatomics, and has the potential to provide systematic mapping of excited state potentials.  This information is critical to the ab initio design of pulses to control chemical reactions.  The second development is the use of the von Neumann time-frequency representation to represent phase and amplitude shaped, ultrashort laser pulses.  The von Neumann basis provides an efficient and intuitive representation that we show has significant practical advantages for distilling pulse mechanisms, mapping quantum control landscapes and for designing efficient closed-loop laser control based on mechanistic building blocks.  The talk will conclude with some speculation about the prognosis for laser control of chemical bond-breaking in the next 5-10 years.