Abstract

Ultrafast photoexcitation of plasmonic nanostructures can produce highly energetic “nonthermal” electrons that generally have a short lifetime (<100fs) determined by electron-electron scattering events that dissipate energy. We report on the unusual ability of gap plasmon metasurfaces to create nonthermal electrons with high efficiency over a broad spectral range. We further characterize their decay mechanisms which is important for potential utilization in ultrafast nanophotonics or optical energy transduction applications.

© 2017 Optical Society of America