Thermally-assisted recording (tar) patterned-media disk drive with optical detection of write synchronization and servo fields

A thermal assisted recording (TAR) patterned-media magnetic recording disk drive comprising:

• a rotatable magnetic recording disk having a plurality of concentric data tracks, each data track patterned into discrete magnetizable data islands separated by nonmagnetic spaces, and a plurality of angularly spaced nondata synchronization fields extending generally radially across the data tracks, each nondata synchronization field patterned into discrete nondata blocks separated by gaps in the along-the-track direction;
• a write head for applying a magnetic field to the data islands;
• a laser light source;
• an optical channel and near-field transducer for directing radiation from the light source to the disk to heat the data islands, the near-field transducer generating a power absorption profile on the disk with a characteristic along-the-track spot size less than the along-the-track length of the gaps between the nondata blocks;
• a carrier for supporting the write head and near-field transducer, the carrier having a disk-facing surface maintained at a distance less than the wavelength of the laser light from the disk;
• a sensor providing an output signal in response to radiation from the nondata blocks and gaps in the synchronization fields as the disk rotates;
• and
• a write clock responsive to said sensor output signal and coupled to the write head for controlling the timing of the magnetic field applied to the data islands by the write head.

A thermal assisted recording (TAR) patterned-media magnetic recording disk drive comprising:

• a rotatable magnetic recording disk having a plurality of concentric data tracks, each data track patterned into discrete magnetizable data islands separated by nonmagnetic spaces, and a plurality of angularly spaced nondata servo sectors extending generally radially across the data tracks, each nondata servo sector patterned into discrete nondata servo blocks separated by gaps in the along-the-track direction;
• a write head for applying a magnetic field to the data islands;
• a laser;
• an optical channel and near-field transducer for directing radiation from the laser to the disk to heat the data islands, the near-field transducer generating a power absorption profile on the disk with a characteristic along-the-track spot size less than the along-the-track length of the gaps between the nondata servo blocks;
• a carrier for supporting the write head and near-field transducer, the carrier having a disk-facing surface maintained at a distance less than the wavelength of the laser light from the disk;
• a sensor providing an output signal in response to radiation from the nondata servo blocks and gaps in the servo sectors as the disk rotates;
• and
• servo electronics responsive to said sensor output signal for controlling the positioning of the write head on the data tracks.