It is proposed to study ultrafast molecular reaction dynamics at single crystal surfaces using femtosecond laser techniques.
The goals are: a) to provide the first experimental determination of the potential energy surface governing desorption and reaction of molecules on solid surfaces.
b) to elucidate the critical population and dephasing dynamics of reacting molecules on surfaces.
The experiments will use a specially dedicated Ti:sapphire laser oscillator with regenerative amplification, giving pulses of about 50 fs pulse width in the visible and mid-IR range.
Pump-probe spectroscopy will monitor the propagation of the molecular adsorbates in the ground electronic state during desorption, including precursor states. Variation of the time delay between pump and probe pulses of varying frequency gives the desired information on the shape of the potential.
In the longer term, multiple pulse spectroscopy will be applied to delineate the energy and phase relaxation of molecular excitations during reactions at surfaces.