Science Daily August 23, 2019
The nano corkscrews are highly sensitive to light: depending on frequency and polarisation, they can strongly enhance it. Usually, the interaction of such nano-antennas with an electromagnetic field is determined using numerical methods. Each helix geometry, however, requires a new numerically expensive calculation. Researchers in Germany have a formula that tells them how a nano-antenna with specific parameters responds to light. This analytical description can be used as a design tool, as it specifies the required geometrical parameters of a nano-helix to amplify electromagnetic fields of desired frequencies or polarisation. The research could have applications in information technology based on the spin quantum number of light and sensor technology in detecting chiral molecular species down to the single molecule level…read more. Open Access TECHNICAL ARTICLE
Geometry of a helical plasmonic antenna. A single plasmonic helix of turns is illuminated by circularly polarized light propagating along the helix axis. Credit: Optica, https://doi.org/10.1364/OPTICA.6.001098