6533b85bfe1ef96bd12bb31a

RESEARCH PRODUCT

Robustness of plasmonic angular momentum confinement in cross resonant optical antennas

Keno L. KrewerBert HechtGerd SchönhenseMartin LehrGary RazinskasXiaofei WuHans-joachim ElmersP. KlaerF. Schertz

subject

PhysicsPhotoemission electron microscopyAngular momentumNanostructurePlanarOpticsPhysics and Astronomy (miscellaneous)business.industrybusinessPolarization (waves)PlasmonExcitationCircular polarization

description

Using a combination of photoemission electron microscopy and numerical simulations, we investigated the angular moment transfer in strongly enhanced optical near-fields of artificially fabricated optical antennas. The polarization dependence of the optical near-field enhancement has been measured in a maximum symmetric geometry, i.e., excitation by a normal incident planar wave. Finite-difference time-domain simulations for the realistic antenna geometries as determined by high-resolution electron microscopy reveal a very good agreement with experimental data. The agreement confirms that the geometrical asymmetries and inhomogeneities due to the nanoscale fabrication process preserve the circular polarization in the gap regions with strong near-field enhancement.

https://doi.org/10.1063/1.4923242