Time-resolved photoelectron angular distributions as a map of rotational motion

We discuss the application of photoelectron angular distributions as a probe of time-evolving rovibrational wavepackets. A physical picture is drawn of the mechanism through which rotation-vibration coupling mechanisms are reflected in the time-dependent photoionisation asymmetry parameters. The effects of complicating features that may obscure the interpretation of time-resolved photoelectron spectroscopies, including the field intensity and the inherent complexity of ionisation processes are examined.