Characterizing plasmon-enhanced photoemitters for bright ultrafast electron beams

Pulsed electron beam sources are increasingly in demand, especially as probes for ultrafast science and as patterning tools in lithography applications. Plasmonic nanostructures have been shown to enhance multiphoton photocurrent from metal cathodes by orders of magnitude, but for many applications it is also important to characterize the transverse electron beam properties. Here, we present preliminary work demonstrating a DC photogun setup for characterizing plasmonic photoemitters at Lawrence Berkeley National Laboratory, including measurement of photocurrent and the asymmetric transverse phase space of photoemitted beams from plasmonic nanogroove resonator arrays. This lays the groundwork for future studies of emerging plasmon-enhanced photoemitter designs, such as plasmonic lens nanoemitters.