Merging metasurfaces with free electrons in the scanning electron microscope

In this webinar, our speaker, Matthias Liebtrau from the Photonic Materials group of AMOLF, will demonstrate how Delmic's SPARC spectral can be used for a nanophotonics application. Join our host, Toon Coenen, Director Materials Science Director of Delmic in this webinar and learn more about how the energy-momentum imaging in the SPARC Spectral is a powerful tool to study Smith-Purcell (SP) radiation. At the end of the webinar, we would be happy to answer any questions and get your feedback!

The recording of the webinar will be available right after the end for all registrants.

A more detailed abstract is given below:

Free electrons constitute a unique tool to excite and probe optical phenomena at nanometer length scales and over an ultra-wide spectral range. In periodic systems, this interaction gives rise to the emission of SP radiation, a phenomenon that can be tuned in frequency by both structural parameters as well as electron energy. In this work, we experimentally demonstrate chirped metagratings that simultaneously emit and focus SP radiation near the grating plane. The corresponding cylindrical emission wavefronts are observed in the far field using in-situ hyperspectral angle-resolved light detection in a scanning electron microscope (SEM) at 30 keV incident electron energy. Our data are found in good agreement with the results of analytical theory as well as a hybrid-simulation approach, combining full-wave numerical near-field calculations with a ray-tracing model of our light collection setup. To further exemplify the wide-ranging functionalities that can be embedded with free-electron-driven light sources, we design a metasurface composed of split-ring-resonator (SRR) meta-atoms to achieve simultaneous SP focusing and tunable polarization control via spatially-selective SRR mode excitation.