Jump to main content
Jump to site search

Issue 43, 2015
Previous Article Next Article

Tailoring chiro-optical effects by helical nanowire arrangement

Author affiliations


In this work, we experimentally investigate the chiro-optical properties of 3D metallic helical systems at optical frequencies. Both single and triple-nanowire geometries have been studied. In particular, we found that in single-helical nanostructures, the enhancement of chiro-optical effects achievable by geometrical design is limited, especially with respect to the operation wavelength and the circular polarization conversion purity. Conversely, in the triple-helical nanowire configuration, the dominant interaction is the coupling among the intertwined coaxial helices which is driven by a symmetric spatial arrangement. Consequently, a general improvement in the g-factor, extinction ratio and signal-to-noise-ratio is achieved in a broad spectral range. Moreover, while in single-helical nanowires a mixed linear and circular birefringence results in an optical activity strongly dependent on the sample orientation and wavelength, in the triple-helical nanowire configuration, the obtained purely circular birefringence leads to a large optical activity up to 8°, independent of the sample angle, and extending in a broad band of 500 nm in the visible range. These results demonstrate a strong correlation between the configurational internal interactions and the chiral feature designation, which can be effectively exploited for nanoscale chiral device engineering.

Graphical abstract: Tailoring chiro-optical effects by helical nanowire arrangement

Back to tab navigation

Supplementary files

Publication details

The article was received on 12 Jul 2015, accepted on 21 Sep 2015 and first published on 25 Sep 2015

Article type: Paper
DOI: 10.1039/C5NR04674B
Author version
Download author version (PDF)
Nanoscale, 2015,7, 18081-18088

  •   Request permissions

    Tailoring chiro-optical effects by helical nanowire arrangement

    M. Esposito, V. Tasco, F. Todisco, A. Benedetti, I. Tarantini, M. Cuscunà, L. Dominici, M. De Giorgi and A. Passaseo, Nanoscale, 2015, 7, 18081
    DOI: 10.1039/C5NR04674B

Search articles by author