Nano-antenna design breakthrough
Nano-antennae produced in an electron microscope by direct electron-beam writing. [HZB]
Researchers from Helmholtz-Zentrum Berlin, Germany, have developed an analytical design tool to show how corkscrew-shaped nano-antennas interact with light.
The mathematical tool can be used to calculate the geometry that a nano-antenna must have to amplify electromagnetic fields of desired frequencies or polarisation for applications in sensor technology or information technology.
“We now have a formula that tells us how a nano-antenna with specific parameters responds to light,” says lead researcher Katja Höflich.
Crucially, Höflich and colleagues have used their tool to fabricate nano-antennae in an electron microscope by using direct electron-beam writing.
As they highlight, the electron beam writes a helix-shaped carbon structure one point at a time, which is them coated with silver.
According to the researchers, the actual measurements of the optical properties for these silver nano-antennae are in good agreement with the calculated properties predicted by the analytical model.
Research is published in Optica.