Optical energy optimization at the nanoscale by near-field interference

TL;DR

This paper demonstrates that off-resonant plasmonic antennas can efficiently transfer optical energy to magnetic recording layers, achieving subdiffraction focusing for potential nanoscale all-optical magnetic data recording.

Contribution

It reveals that off-resonant antennas optimize energy transfer and achieve subdiffraction focusing in magnetic media, advancing nanoscale optical data storage.

Findings

Optimal energy transfer occurs with off-resonant antennas.

Focal spot size is below the diffraction limit.

Nanoscale all-optical magnetic recording is feasible.

Abstract

Employing plasmonic antennas for subdiffraction focusing of light on recording media requires to take into account the complete structure of the medium, including dielectric cover layers. We find, with finite difference time domain simulations, that optical energy transfer to the magnetic recording layer is most efficient for an off-resonant antenna. Furthermore, we show that the focal spot in the magnetic film is well below the diffraction limit, making nanoscale all-optical magnetic data recording achievable.