POLARIZATION ROTATOR FOR THERMALLY ASSISTED MAGNETIC RECORDING

摘要

A waveguide structure with a light polarization rotator section for converting transverse electric light from a TE light source to transverse magnetic light which is subsequently coupled to a plasmon generator (PG) is disclosed. Wavelengths above 800 nm are advantageously used to reduce resistive heating in the PG, and in adjacent cladding and write pole layers to improve the thermally assisted magnetic recording head lifetime. The light polarization rotator section has a length determined by TE LD light wavelength, and the effective mode index of the two orthogonal fundamental modes, and has curved portions to enable a greater length to accommodate longer TE light wavelengths without increasing the waveguide distance between the air bearing surface and back end of the device.

主权项

1. A waveguide in a thermally assisted magnetic recording (TAMR) head comprising:
(a) a first section with a first width and a first end at a back end of a slider, the first end receives transverse electric (TE) light from an adjoining laser diode (LD), and a second end that is connected to the first end by two parallel sides which are aligned in a first axis direction that is perpendicular to an air bearing surface (ABS); (b) a tapered section having a first width in a cross-track direction at a first end that adjoins the second end of the first section, and a second width in a cross-track direction at a second end that faces the ABS wherein the second width is less than the first width, the tapered section narrows a beam of TE light that is propagated toward the ABS; (c) a first sub-section with a first portion that has the second width in a cross-track direction between two sides that are aligned in the first axis direction, and a first end adjoining the second end of the tapered section, and with a second portion having curvature that has a second end facing away from a center plane that bisects the first sub-section along the first axis direction; (d) a second sub-section with a first portion that has the second width between two sides that are aligned perpendicular to the ABS, and a first end adjoining the ABS, and with a second portion having curvature that has a second end facing away from the center plane, light propagated through the second sub-section is coupled to an adjacent plasmon generator (PG); and (e) a light polarization rotator section for converting TE light from the first sub-section into transverse magnetic (TM) light which enters the second sub-section and is then coupled to the PG, comprising; (1) a first linear section aligned in a cross-track direction and with an end adjoining the second end of the curved second portion of the first sub-section; (2) a second linear section formed parallel to the first linear section and adjoining the second end of the curved second portion of the second sub-section; and (3) a curved section formed between the first linear section and the second linear section.