Cavity-QED with a single ion
Radio-frequency ion-traps provide ideal conditions for storing and manipulating single particles and localizing them with a precision far below their resonance wavelength. This property is applied in our experiment to investigate the interaction between ions and the field in an optical cavity, implementing a completely deterministic dynamical evolution of the system. This is in contrast to previous cavity QED experiments using atomic beams  or atomic fountains . In these cases, deterministic control over the motion of the atoms is not possible, because the randomly varying arrival times and trajectories result in a fluctuating atom-field interaction strength. In the ion-based cavity-QED system we have set up, a continuous interaction of a single particle with the photon field at a pre-defined position is realized. Applications include the generation of single photon pulses as well as a single-ion laser.