Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer
Abstract
Although near-field microscopy has allowed optical imaging with sub-20 nm resolution, the optical throughput of this technique is notoriously small. As a result, applications such as optical data storage have been impractical. However, with an optimized near-field transducer design, we show that optical energy can be transferred efficiently to a lossy metallic medium and yet remain confined in a spot that is much smaller than the diffraction limit. Such a transducer was integrated into a recording head and flown over a magnetic recording medium on a rotating disk. Optical power from a semiconductor laser at a wavelength of 830 nm was efficiently coupled by the transducer into the medium to heat a 70-nm track above the Curie point in nanoseconds and record data at an areal density of ~375 Tb m-2. This transducer design should scale to even smaller optical spots.
- Publication:
-
Nature Photonics
- Pub Date:
- April 2009
- DOI:
- 10.1038/nphoton.2009.26
- Bibcode:
- 2009NaPho...3..220C