Figure 1. Laser-induced electron diffraction from aligned C₂H₂ molecules using a mid-infrared OPCPA source and a reaction microscope.

The cartoon film shows the procedure. (a) The C₂H₂ molecules are pre-aligned by focusing the 1.7 μm pump pulse (blue) into a molecular jet. (b) The 3.1 μm pulse (red) is used to generate high-energy electrons that subsequently rescatter off the parent ion. (c) The rescattered electrons carry structural information of the parent ion that is contained in the detected angular momentum distributions. The anticollinear electric (E) and magnetic (B) fields guide the charged fragments towards opposing position-sensitive detectors.