Credit: Matthew Sykes, Argonne National Laboratory, Shutterstock / Triff and Shutterstock / siro46
The figure in the foreground shows near-infrared and broadband light pulses (squiggly lines at top) striking a silver nanocube measuring 150 nanometers square. The near-infrared pulse excites electrons in the nanostructure, while the broadband pulse monitors their optical response. An aluminum oxide spacer separates the nanocube from a gold film with a thickness of 50 nanometers. The spacer measures between 1 and 25 nanometers thick. A water molecule, by comparison, is approximately 1.5 nanometers in diameter.