Collision spectroscopy with optically prepared targets

The possibility of optical target preparation has added new dimensions to a tomic collision spectroscopy By suitable choices of photon wavelength and p olarization, the shape and dynamics of the target atom can be controlled an d manipulated before the interaction with the projectile. Similarly, the sh ape and dynamics of the atomic states in the exit channel can be monitored by polarization analysis of the photons emitted in the subsequent optical d ecay. Finally, the target temperature maybe strongly reduced by laser cooli ng and used for recoil ion momentum spectroscopy. A series of simple exampl es are presented in order to demonstrate the kind of insight into the inter action dynamics that may be gleaned from combined experimental and theoreti cal studies of this kind.