Light Delivery Techniques for Heat-Assisted Magnetic Recording

Abstract

Heat-assisted magnetic recording (HAMR), also known as hybrid recording, has been proposed to enable storage densities greater than 1 Tb/in 2 in hard disc drives while circumventing the superparamagnetic limit. Light is delivered in the near field to the recording medium to heat just the spot which is to be recorded. Techniques based on apertures, antennas, waveguides, and solid immersion lenses have been suggested for delivering substantial amounts of optical power into subwavelength spots in the near field. A practical transducer for HAMR may require a combination of techniques.

All-Optical Magnetic Recording with Circularly Polarized Light

“…week ending 27 JULY 2007 047601-2 recently developed heat assisted magnetic recording scheme [26], but with the major difference that the laser pulse in our case not only heats the medium, but does this ultrafast and simultaneously acts as a magnetic field. The above described picture suggests that by simply reducing the laser power one should be able to cleanly reverse the magnetization in the center of the excited area without causing overheating and demagnetization.…”

“…4(b) how optically written bits can be overlapped and made much smaller than the beam waist by modulating the polarization between and ÿ as the laser beam is swept across the sample. High density recording may also be achieved by employing especially designed near-field antenna structures [26] such as those currently being developed for heat assisted magnetic recording. With the recent development of compact ultrafast laser systems [32] and the successful incorporation of lasers in magnetic storage devices [26], the present demonstration of ultrafast and all-optical magnetization reversal might spur the realization of a new generation of magnetic recording devices.…”

Plasmonic near-field transducer for heat-assisted magnetic recording

“…The dimensions of both the resonator and the sharp feature need to be optimized to achieve the best energy coupling efficiency. Common designs include triangle antenna [28,29] and triangle aperture [30,31], C aperture [32][33][34][35][36], bowtie antenna [37][38][39][40] and bowtie aperture [15,23,[41][42][43][44].…”

Nanomechanical Control of an Optical Antenna

“…Resonant optical nanoantennas hold great promise for applications in physics and chemistry [1][2][3][4][5][6] . Their operation relies on their ability to concentrate light on spatial scales much smaller than the wavelength.…”

“…Metal nanoantennas, the down-scaled optical analogues of radio antennas, are promising systems for applications in nanometre-scale lithography 1 , field-enhanced spectroscopy 2 , nanoscopic light emitters with tailored absorption and emission characteristics [3][4][5] , light harvesting, high-density optical data storage, and laser-assisted magnetic recording 6 . A second fundamental property of these metallic nanostructures is the extreme sensitivity of the plasmon resonances to their surroundings.…”