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Updated: May 8, 2026

Plasmonic Trapping and Release of Nanoparticles in a Monitoring Environment
Published on: April 4, 2017
Coupling strength can control the polarization twist of a plasmonic antenna
Banafsheh Abasahl1, Shourya Dutta-Gupta, Christian Santschi
1Nanophotonics and Metrology Laboratory (NAM), Swiss Federal Institute of Technology Lausanne (EPFL) , 1015 Lausanne, Switzerland.
Abstract:
The far-field polarization of the optical response of a plasmonic antenna can be tuned by subtly engineering of its geometry. In this paper, we develop design rules for nano antennas which enable the generation of circular polarized light via the excitation of circular plasmonic modes in the structure. Two initially orthogonal plasmonic modes are coupled in such a way that a rotational current is excited in the structure. Modifying this coupling strength from a weak to a strong regime controls the helicity of the scattered field. Finally, we introduce an original sensing approach that relies on the rotation of the incident polarization and demonstrates a sensitivity of 0.23 deg·nm(-1) or 33 deg·RIU(-1), related to changes of mechanical dimensions and the refractive index, respectively.
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