Quantum and semiclassical dynamics of differential optical collisions

We apply quantum and semiclassical theories to differential optical collisions Na(3(2)S(1/2)) + Kr + (h) over bar omega --> Na(3(2)P(1/2), (3/2)) + Kr. Our results provide a basis to analyze recent experiments in which for the first time optical collisions were investigated with angular resolution under crossed-beam conditions. A characteristic feature of the differential cross sections is the pronounced oscillatory structure due to interferences of different Condon paths. These Stueckelberg oscillations form an extremely sensitive probe of the collisional dynamics and of the molecular interactions. We demonstrate perspectives to determine geometric properties of the collision complex by excitation with polarized light. By final state analysis nonadiabatic (spin-orbit, rotational) interactions can be studied with complete control of the path. In summary it is shown that the method of differential detection of optical collisions opens a variety of new accesses to atomic and molecular subcollisions.