8-12 July 2019
Cité des Congrès
Europe/Paris timezone

Subwavelength polarization optics via helical travelling-wave nanoantennas

11 Jul 2019, 10:15
15m
Salle GH (Cité des Congrès)

Salle GH

Cité des Congrès

Speaker

Dr Thierry Grosjean (Institut FEMTO-ST)

Description

A wide variety of optical applications and techniques require control of light polarization. To date, there has been no experimental demonstration of tunable polarization control with individual subwavelength devices.

We present and demonstrate the concept of a helical travelling-wave nanoantenna (HTN) consisting of a tiny gold-coated helix end-fired with a rectangular aperture nanoantenna (Fig. 1(a)). The resulting non-resonant hybrid nanoantenna produces a light beam of tunable polarization (elliptical up to circular states) by swirling surface plasmons and taking advantage of optical spin-orbit interaction (Fig. 1(b)).

Four closely packed HTNs are shown to locally convert an incoming light beam into four beams of tunable polarizations and intensities. Moreover, by coupling HTNs of opposite handedness (Fig. 1(c)), we demonstrated a subwavelength waveplate-like structure providing a degree of freedom in polarization control that is forbidden with usual polarization optics and metamaterials.

Figure 1: (a) Scanning electron micrograph of a fabricated HTN. (b) Experimental polarization diagram of the HTN emission at a wavelength of 1.64 microns. (c) Scanning electron micrograph of a subwavelength waveplate-like structure made of four coupled HTNs of opposite handedness.

Choix de session parallèle 5.3 SFO: Metamatériaux, plasmonique

Primary authors

Dr Mengjia Wang (Institut FEMTO-ST) Dr Roland Salut (Instituit FEMTO-ST) Dr Huihui Lu (Jinan University) Dr Miguel Angel Suarez (Institut FEMTO-ST) Prof. Nicolas Martin (Institut FEMTO-ST) Dr Thierry Grosjean (Institut FEMTO-ST)

Presentation Materials