Double Helical Plasmonic Antennas
A. Tsarapkin1, L. Zurak2, K. Maćkosz3, L. Löffler2, V. Deinhart1,4, I. Utke3, T. Feichtner2, and K. Höflich1
Published in:
Adv. Funct. Mater., vol. 36, no. 20, pp. 2507471, doi:10.1002/adfm.202507471 (2026).
Abstract:
Plasmonic double helical antennas are a means to funnel circularly polarized light down to the nanoscale. Here, an existing design tool for single helices is extended to the case of double helices and used to design antennas that combine large chiroptical interaction strength with highly directional light emission. Full-field numerical modeling underpins the design and provides additional insight into surface charge distributions and resonance widths. The helical antennas are fabricated by direct writing with a focused electron beam, a technique that is unrivaled in terms of spatial resolution and 3D shape fidelity. After the printing process, the structures are purified using ozone plasma at room temperature, resulting in the smallest continuous double helix antennas ever realized in gold. Fabricated antennas are studied regarding their polarization-dependent transmission behavior, which shows a large and broadband dissymmetry factor in the visible range. Since the polarization of light is an important tool for implementing logic functionality in photonic and quantum photonic devices, these helices are potential building blocks for future nanophotonic circuits, but also for chiral metamaterials or phase plates.
1 Ferdinand-Braun-Institut (FBH), Gustav-Kirchhoff-Str. 4, D-12489 Berlin, Germany
2 Experimental Physics, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
3 Laboratory for Mechanics of Materials and Nanostructures, Empa – Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkerstrasse 39, Thun CH-3602, Switzerland
4 Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Str. 2A, D-12489 Berlin, Germany
Keywords:
chiroptical interaction; circular dichroism; focused electron-beam induced deposition; helical antenna; plasmonics
© 2025 The Author(s). Advanced Functional Materials published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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