A schematic describing the geometry of the bullseye lens, showing the grating period (p), groove width (w), groove depth (d), and the center plateau radius (r).
Scientific Achievement
A collaboration between the Molecular Foundry and Berkeley Lab’s Accelerator Technology and Applied Physics division has developed a bullseye plasmonic lens for ultrafast electron sources capable of sub-10 femtosectond pulses.
Significance and Impact
This is a novel design for plasmonic lenses that will enable the next generation of electron sources, bridging the gap in spatial resolution between static and ultrafast sources and allowing for characterization of nanoscale dynamics.
Research Details
- The researchers first used electromagnetic simulations to demonstrate how to control the characteristics of the optical fields and the corresponding photoemission by geometric design.
- They demonstrated fabrication of actual bullseye lenses in gold films by two methods and characterized their plasmonic behavior using cathodoluminescence spectromicroscopy.
- The team showed that spatial and spectral plasmonic characteristics are predicted in simulation, supporting that ultrafast nano-emission can be achieved.
