Atomic Rydberg ionization dynamics out of an optical dipole trap

Cold-target recoil ion momentum spectroscopy (COLTRIMS) with optically cooled and trapped atomic targets has proven to be a very powerful tool to study atomic ionization dynamics in great detail and with high resolution. Here we investigate how the trapping field of a far-off resonance optical dipole trap can affect such experiments. Specifically, the break-up of optically trapped lithium atoms is observed, which are excited in a femtosecond laser pulse and subsequently ionized in the field of a near-infrared continuous-wave trapping laser. We measure the photoelectron angular and energy distributions as well as the time after the arrival of the femtosecond laser pulse at which the ionization takes place. This allows studying the effect of the trapping laser field on the atomic dynamics and provides information on the time-dependent population transfer of bound and continuum states.