Beaming of helical light from plasmonic vortices via adiabatically tapered nanotip

Abstract

We demonstrate the generation of far-field propagating optical beams with a desired orbital angular momentum by using a smooth optical mode transformation between a plasmonic vortex and free space Laguerre-Gaussian modes. This is obtained by means of an adiabatically tapered gold tip surrounded by a spiral slit. The proposed physical model, backed up by the numerical study, brings about an optimized structure which is fabricated by using highly reproducible secondary electron lithography technique. Optical measurements of the structure excellently agree with the theoretically predicted far-field distributions. This architecture provides a unique platform for a localized excitation of plasmonic vortices followed by its beaming.

Nano Letters, 2016

References in corpus (3)

• Observation of the spin-based plasmonic effect in nanoscale structures
• Strong coupling of single emitters to surface plasmons
• Beaming of helical light from plasmonic vortices via adiabatically tapered nanotip

Cited by in corpus (4)

• Beaming of helical light from plasmonic vortices via adiabatically tapered nanotip
• Orbital-to-Spin Angular Momentum Conversion Employing Local Helicity
• Magnetic Control of Transmission and Helicity of Nano-Structured Optical Beams in Magnetoplasmonic Vortex Lenses
• Helicity locking in light emitted from a plasmonic nanotaper