Efficient excitation of a monopole optical transducer for near-field recording

Abstract

An optical near-field transducer composed of a rectangular patch and a protruded peg has been numerically studied for heat-assisted magnetic recording. This transducer strongly interacts with a planar solid immersion focusing field and efficiently couples optical energy into a recording medium in a region determined by the peg cross-section. The transducer is excited through the electric field predominantly normal to its edges. The optimal size of the rectangular patch is found to be a half-wave optical antenna in height and between half-wave and full-wave in width.

Novel droplet near-field transducer for heat-assisted magnetic recording

“…2(a) and (c) and with the thickness of the antenna -composed of gold -being of 20 nm corresponds to a quadrupole excited mode with a resonant wavelength of λ = 810 nm with an image plane (assumed gold to represent the recording media) placed at a distance of 7.5 nm from the termination of the peg. The cross-section of the electric field enhancement at a distance of 7 nm from the peg (0.5 nm from the image plane) in the plane perpendicular to the transducer and taken at the center of the peg width revealed a field enhancement of~20 and a hotspot/sidelobe ratio around 5.6, which is a good fit to both experimental [34] and previously reported theoretical data [35]. Simultaneously, the hotspot width of 37 nm, determined from the simulations, is mostly determined by the peg dimensions.…”

“…2) [14,19,34] has earned a lot of interest because of its functionality, efficiency, and small spot size. Furthermore, it enables easy integration with a planar waveguide geometry and, as a consequence, with a laser light source.…”

Nanoscale sub-100 picosecond all-optical magnetization switching in GdFeCo microstructures

“…Third, it is possible to write the desired 'up' or 'down' magnetic domain orientation by selecting the appropriate left-or right-handed circularly polarized laser pulse, taking advantage of the magnetic circular dichroism of the recording media in combination with the threshold behaviour of AOS 29 . Finally, laser pulses can be focused with plasmonic antennae to spot sizes of a few tens of nanometres [30][31][32][33] . However, whether nanoscale sub-100 ps alloptical magnetization switching is feasible remains to be tested.…”

Plasmonic near-field transducer for heat-assisted magnetic recording

“…The SP resonances in lollipop both without and with the presence of the medium have been experimentally characterized via a pump-probe photothermal measurement and by taking AFM topography of illuminated devices [51]. In addition, the disk resonator can be replaced by a rectangular resonator to enhance the excitation efficiency [52]. The nanobeak antenna [50,53,54] is essentially a triangular antenna with a 3D beaked apex, as shown in Figure 7D.…”