In our Perspective Article "Dynamic Imaging of Molecules using High Order Harmonic Generation" we present the first steps towards realising a new way of imaging molecular structure and intra-molecular dynamics in "real time". 

We use the optical carrier wave from an intense laser as a "clock" to measure the dynamics with a resolution of less than 1/10th of an optical cycle. Since the optical cycle time is just 2.7fs we have been able to measure events with a time resolution of only a hundred attoseconds. These are, to our knowledge, the fastest measurements of intra-molecular dynamics ever to be made. The strong laser field drives high momentum electrons that probe instantaneously the molecular structure so that the measurements yield both sub-femtosecond temporal and sub-Angstrom spatial resolution. So far these techniques have only been applied to small molecules (diatomic and triatomic) but the application to polyatomic molecules has started to be explored.

It is the longer term objective of this work to measure sub-femtosecond intra-molecular electronic and proton dynamics in a range of systems. In this way new insights into the fundamental many-body quantum physics of molecules will be gained. Further, we anticipate that these methods will enable us to follow the changes in molecular structure that accompany a chemical reaction. However, as we highlight in the article, many technical and theoretical challenges must be overcome to achieve this goal.