Thermally-assisted recording (TAR) disk drive with patterned multilevel media and laser with power modulation

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

• a rotatable magnetic recording disk having a generally planar surface supporting a plurality of concentric data tracks, each data track patterned into discrete data islands separated by nonmagnetic spaces, each island comprising two stacked cells of magnetic material magnetizable generally perpendicular to the disk surface and separated by a nonmagnetic spacer, the upper cell in the stack having a Curie temperature TC1 and the lower cell in the stack having a Curie temperature TC2 greater than TC1;
• a disk drive data controller for controlling the data to be written to the data islands;
• a write head for applying to the data islands a magnetic write field insufficient to magnetize the cells when the cells are at a temperature substantially below their Curie temperatures;
• a laser coupled to the data controller and responsive to the data to be written to the data islands for supplying two levels of laser output power, a first laser power P1 for data corresponding to the magnetizations in the two cells of an island being antiparallel and a second level of laser power P2 greater than P1 for data corresponding to the magnetizations in the two cells of an island being parallel;
• an optical channel and near-field transducer for directing radiation from the laser to the disk to heat the data islands;
• wherein laser power P1 heats the upper cell in an island to a temperature near TC1 but less than TC2 and laser power P2 heats the lower and upper cells in an island to a temperature greater than TC1 and near TC2;
• and
• 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.