Plasmonic Helical Nanoantenna As a Converter between Longitudinal Fields and Circularly Polarized Waves.
Nano Lett
; 21(8): 3410-3417, 2021 Apr 28.
Article
en En
| MEDLINE
| ID: mdl-33830778
ABSTRACT
A wide variety of optical applications and techniques require control of light polarization. So far, the manipulation of light polarization relies on components capable of interchanging two polarization states of the transverse field of a propagating wave (e.g., linear to circular polarizations, and vice versa). Here, we demonstrate that an individual helical nanoantenna is capable of locally converting longitudinally oriented confined near-fields into a circularly polarized freely propagating wave, and vice versa. To this end, the nanoantenna is coupled to cylindrical surface plasmons bound to the top interface of a thin gold layer. Helices of constant and varying pitch lengths are experimentally investigated. The reciprocal conversion of an incoming circularly wave into diverging cylindrical surface plasmons is demonstrated as well. Interconnecting circularly polarized optical waves (carrying spin angular momentum) and longitudinal near-fields provides a new degree of freedom in light polarization control.
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Bases de datos:
MEDLINE
Idioma:
En
Revista:
Nano Lett
Año:
2021
Tipo del documento:
Article
País de afiliación:
Francia