Studying caustics with a pulsed atom laser

In a recent series of experiments, our group has demonstrated the emergence of caustics in a quasi-continuous atom laser. A rich phenomenology, including fold and cusp singularities and larger caustic networks, has been observed. Here, we first provide theoretical background for these studies and then extend them by presenting results obtained with a pulsed, rather than quasi-continuous, atom laser. Our experiments with pulsed atom lasers reveal additional insight: for example, some caustics are actual particle trajectories, while others only appear as envelops of trajectories. These studies advance our understanding of catastrophe atom optics and provide new tools for future atom optical experiments.