Confined circularly polarized light generated by nano-size aperture for high density all-optical magnetic recording

Abstract

It is revealed by the finite difference time domain simulation that a cross aperture antenna can create a localized circularly polarized light, 10 nm in diameter, on the surface of a recording medium. The confined circularly polarized light on the surface, however, expands in the recording layer. We eventually find that the newly proposed modified cross aperture in combination with particle medium leads to confinement of a circularly polarized light in the particle. This proposed combination of a surface plasmon antenna/aperture and recording particles is one of the strategies to achieve high speed and high density for all-optical magnetic recording.

Dependence of Circularly Polarized Light Excited by Plasmon Aperture on Relative Position to Magnetic Particles for All-Optical Magnetic Recording

“…Most of all the researches, however, have not taken the effect of media into account in their simulations. We reported 6,9) that a localized circularly polarized light was created by a nano-size four-fold aperture. A condition of a surface plasmon resonance is extremely sensitive to not only the antenna shape but also the counter medium shapes and positions 10) .…”

“…In order to reduce a magnetic domain size, some nano-size antennas were reported by several groups [4][5][6][7][8][9] . Most of all the researches, however, have not taken the effect of media into account in their simulations.…”

Nanostructuring of GdFeCo Thin Films for Laser Induced Magnetization Switching

“…To circumvent this problem, a plasmonic antenna, which conserves the circular polarization of the laser pulse and focuses it in a few tens of nanometer region, has been proposed 4) . These properties are unfortunately lost when the antenna is brought in close contact with the continuous metallic recording layer, but can be preserved if this layer is structured in individually addressable recording bits 5) . Focus ion beam patterning can be used to pin the domain wall in similar materials by locally reducing the out-of-plane magnetic anisotropy 6,7) .…”

Efficient Analysis of Electromagnetic Fields for Designing Nanoscale Antennas by Using a Boundary Integral Equation Method With Fast Inverse Laplace Transform

“…In this paper, electromagnetic problems for nanoscale antennas are investigated by a boundary integral equation method with fast inverse Laplace transform (BIEM-FILT) [3,4]; novel antennas are designed to realize ultra-fast and high-density magnetic recording using localized circularly polarized light [5][6][7][8]. For this state-of-the-art technology, high intensity and localized circularly polarized light is required near the antenna.…”