Magnetic and Electric Transverse Spin Density of Spatially Confined Light

Magnetic and Electric Transverse Spin Density of Spatially Confined Light

Neugebauer, Martin (Max Planck Institute for the Science of Light; Friedrich-Alexander-Universität Erlangen-Nürnberg)
Eismann, Jörg S. (Max Planck Institute for the Science of Light; Friedrich-Alexander-Universität Erlangen-Nürnberg)
Bauer, T.A. (TU Delft QN/Kuipers Lab)
Banzer, Peter (Max Planck Institute for the Science of Light; Friedrich-Alexander-Universität Erlangen-Nürnberg)

2018

When a beam of light is laterally confined, its field distribution can exhibit points where the local magnetic and electric field vectors spin in a plane containing the propagation direction of the electromagnetic wave. The phenomenon indicates the presence of a nonzero transverse spin density. Here, we experimentally investigate this transverse spin density of both magnetic and electric fields, occurring in highly confined structured fields of light. Our scheme relies on the utilization of a high-refractive-index nanoparticle as a local field probe, exhibiting magnetic and electric dipole resonances in the visible spectral range. Because of the directional emission of dipole moments that spin around an axis parallel to a nearby dielectric interface, such a probe particle is capable of locally sensing the magnetic and electric transverse spin density of a tightly focused beam impinging under normal incidence with respect to said interface. We exploit the achieved experimental results to emphasize the difference between magnetic and electric transverse spin densities.

http://resolver.tudelft.nl/uuid:12da8ec1-eb18-4d04-b631-cda2550907e1

https://doi.org/10.1103/PhysRevX.8.021042

2160-3308

Physical Review B, 8 (2)

Institutional Repository

journal article

© 2018 Martin Neugebauer, Jörg S. Eismann, T.A. Bauer, Peter Banzer