System, method and apparatus for internal polarization rotation for horizontal cavity, surface emitting laser beam for thermally assisted recording in disk drive

A disk drive, comprising:

• an enclosure;
• a disk rotatably mounted to the enclosure and having magnetic media with concentric tracks;
• an actuator having a slider with a magnetic write pole for writing data to the disk;
• the slider further comprising:
• a slider body having an air bearing surface (ABS) adjacent the magnetic write pole, and a waveguide with an optical near field aperture adjacent the disk;
• and
• a laser mounted to the slider body for emitting a beam that is directed through the waveguide onto the disk for thermally assisted recording (TAR), the beam being reflected by two facets before exiting the laser and entering the waveguide for aligning a polarization of the beam with a direction of the concentric tracks.

A disk drive, comprising:

• an enclosure;
• a disk rotatably mounted to the enclosure and having magnetic media with concentric tracks;
• an actuator having a slider with a magnetic write pole for writing data to the disk;
• the slider further comprising:
• a slider body having an air bearing surface (ABS) adjacent the magnetic write pole, and a waveguide with an optical near field aperture adjacent the disk;
• a laser, comprising a horizontal cavity, surface emitting laser (HCSEL), mounted to the slider body opposite the ABS for emitting a beam that is directed through the waveguide onto the disk for thermally assisted recording (TAR), the beam being reflected by two facets before exiting the laser and entering the waveguide for aligning a polarization of the beam with a direction of the concentric tracks;
• wherein
• the beam emitted by the laser is initially parallel to the disk and the polarization of the beam is orthogonal to the direction of the concentric tracks, a first one of the facets reflects the initial beam in an orthogonal direction that is parallel to the disk and maintains the polarization of the beam, and a second one of facets reflects the beam from said first one of the facets toward the disk, changes the polarization of the beam to align with the direction of the concentric tracks, and directs the beam into the waveguide, through the optical near field aperture, and onto the disk adjacent the magnetic write pole.

A method of forming facets in a laser, comprising:

• (a) providing a laser diode having a longitudinal axis, a lateral axis, and a transverse axis, and a surface extending in a plane defined by the longitudinal and lateral axes and perpendicular to the transverse axis;
• (b) masking the surface of the laser diode and providing two windows in the mask;
• and then
• (c) emitting a single ion beam at the masked laser diode to simultaneously form two facets in the laser diode with the single ion beam through the two windows, such that a first one of the facets is formed on the longitudinal axis and oriented at an angle to the longitudinal and lateral axes but parallel to the transverse axis, and a second one of the facets is laterally spaced apart from but transversely aligned with the first one of the facets, parallel to the longitudinal axis, and oriented at an angle to the lateral and transverse axes.