Abstract
Resonant plasmonic helices have been widely utilized for locally enhancing and tailoring optical chirality. Here we investigate their nonresonant operation through the recently introduced concept of a plasmonic helical “traveling-wave” nanoantenna. Relying on the coupling of a nonresonant plasmonic helix and a nano-aperture, the helical traveling-wave nanoantenna transmits circularly polarized light with the same handedness as the helix and blocks the other, with a measured dissymmetry factor larger than 1.92 (maximum value of 2). This chiroptical transmission is spatially localized, spectrally broadband, and background-free. Finally, we demonstrate the possibility to engineer such a plasmonic helical nanoantenna at the apex of a sharp tip typically used in scanning near-field microscopies, thus opening the route for moveable, broadband, and background-free chiroptical probes.
© 2019 Optical Society of America
Full Article | PDF ArticleMore Like This
Katja Höflich, Thorsten Feichtner, Enno Hansjürgen, Caspar Haverkamp, Heiko Kollmann, Christoph Lienau, and Martin Silies
Optica 6(9) 1098-1105 (2019)
Ren-Chao Jin, Jia-Qi Li, Lin Li, Zheng-Gao Dong, and Yongmin Liu
Opt. Lett. 44(2) 319-322 (2019)
Jingxuan Wei and Chengkuo Lee
Opt. Lett. 44(24) 6041-6044 (2019)