Reconfigurable exciton-plasmon interconversion for nanophotonic circuits

The circle of light conversion on a nanochip

13 December 2017

Computers could perform at light speed using miniature circuits that combine electronics and photonics on a single nanochip.

Using light to send information through a circuit at the nanometre scale is difficult as its wavelength is larger than the width of the tiny wires involved. This can be overcome by using surface plasmons — electromagnetic waves on the surface of the wire — to manipulate the light rushing through the circuit.

A South Korean team, including researchers from the Institute for Basic Science, built optical circuit components by overlaying silver nanowires on thin transition metal semiconductors. They used a laser to generate surface plasmons in the silver nanowire. These plasmons are converted to excitons by the semiconductor, and back to surface plasmons in the nanowire, to eventually be emitted as light.

“This is the first time that we can complete the circle going from plasmons to excitons and back to plasmons” says one of the authors. The technique may enable rapid information processing in tiny devices.

Supported content

References

1. Nature Communications 7, 13663 (2016). doi: 10.1038/ncomms13663