Work

Unidirectional sub-diffraction waveguiding based on optical spin–orbit coupling in subwavelength plasmonic waveguides

Year: 2015

Type: article

Abstract: Subwavelength plasmonic waveguides show the unique ability of strongly localizing (down to the nanoscale) and guiding light. These structures are intrinsically two-way optical communication channels, providing two opposite light-propagation directions. As a consequence, when light is coupled to these planar integrated devices directly from the top (or bottom) surface using strongly focused beams, it is equally shared into the two opposite propagation directions. Here, we show that symmetry can be broken over a broad spectral bandwidth by using incident circularly polarized light, on the basis of a spin-orbital angular momentum transfer directly within waveguide bends. We predict that up to 94% of the incoupled light is directed into a single propagation channel of a gap plasmon waveguide. Unidirectional propagation of strongly localized optical energy, far beyond the diffraction limit, becomes switchable by polarization, with no need of intermediate nano-antennas/scatterers as light directors. This study may open new perspectives in a large panel of scientific domains, such as nanophotonic circuitry, routing and sorting, optical nanosensing, and nano-optical trapping and manipulation.

Source: Optics Letters

DOI: 10.1364/ol.40.002890

Authors: Yannick Lefier, Thierry Grosjean

Institutions: Centre National de la Recherche Scientifique, Franche-Comté Électronique Mécanique Thermique et Optique - Sciences et Technologies, Université de Franche-Comté

Language: English

Topic: Plasmonic and Surface Plasmon Research

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funder: Agence Nationale de la Recherche

Award: Systèmes intelligents intégrés au cœur de la matière