Generation of Pure OAM Beams with a Single State of Polarization by Antenna-Decorated Microdisk Resonators

Kévin G Cognée (1, 2) , Hugo M Doeleman (1, 3) , Philippe Lalanne (2) , A Femius Koenderink (1, 3)

1 Center for Nanophotonics
2 LP2N - Laboratoire Photonique, Numérique et Nanosciences
3 Van der Waals-Zeeman Institute, University of Amsterdam

We report waveguide-addressed plasmonic−photonic resonators that generate beams of controlled orbital angular momentum and spin angular momentum content upon driving through a waveguide. From phase-gradient metasurfaces, we borrow the idea of carefully combining multiple nanoscale resonators in a repeat unit, from which we build periodic rings that decorate microdisk resonators. We describe the general mode structure of microdisk cavities perturbed by antenna arrays on the basis of a quasinormal mode formalism and present a strategy to simultaneously control the orbital and spin angular momentum content of light outcoupled to the far field. We propose a realization that uses silicon nitride disks and aluminum nanorod antennas. We find excellent polarization and orbital angular momentum (OAM) purity, as benchmarked by polarization-resolved interferometric Fourier microscopy on single devices.

Keywords: 3049−3060 Read Online Metrics & More Article Recommendations localized plasmons; microcavities; orbital angular momentum beams; polarization control; hybrid plasmonic−photonic resonators; phase-gradient metasurface; Fourier microscopy

Domains: Optics [physics.optics]

Kévin G Cognée, Hugo M Doeleman, Philippe Lalanne, A Femius Koenderink. Generation of Pure OAM Beams with a Single State of Polarization by Antenna-Decorated Microdisk Resonators. ACS photonics, 2020, 7, pp.3049 - 3060. ⟨10.1021/acsphotonics.0c01081⟩. ⟨hal-03038304⟩