Photon-induced near-field electron microscopy

Optical near-field microscopes can beat the optical diffraction limit when probing electromagnetic fields in the vicinity of microscopic objects, but cannot match the atomic-scale resolution of an electron microscope. Barwick et al. have now developed an ingenious blend of these two imaging modalities — they show how the enhanced electron–photon interactions mediated by these evanescent electromagnetic fields can be detected using an ultrafast electron microscope, generating images of these fields that are well resolved in space and time. This work demonstrates the potential of photon-induced imaging in general and for nanoscale studies of fields at interfaces in particular.