Patent ID: 8089831

Claim:
A heat-assisted magnetic recording head comprising: a medium facing surface that faces a magnetic recording medium; a magnetic pole that has an end face located in the medium facing surface and produces a write magnetic field for writing data on the magnetic recording medium; a waveguide that propagates light; and a plasmon generator, wherein: the waveguide has an evanescent light generating surface that generates evanescent light based on the light propagated through the waveguide; the plasmon generator has an outer surface including a surface plasmon exciting surface, and has a near-field light generating part located in the medium facing surface, the surface plasmon exciting surface being a flat surface that faces the evanescent light generating surface with a predetermined distance therebetween; a surface plasmon is excited on the surface plasmon exciting surface through coupling with the evanescent light generated from the evanescent light generating surface; the near-field light generating part generates near-field light based on the surface plasmon excited on the surface plasmon exciting surface; the surface plasmon exciting surface includes a width changing portion, the width changing portion having a width that decreases with decreasing distance to the medium facing surface, the width being in a direction parallel to the medium facing surface and the evanescent light generating surface; the width changing portion has two sides that lie on opposite sides in the direction of the width; each of the two sides forms an angle in the range of 3 to 50 degrees with respect to a direction perpendicular to the medium facing surface; the magnetic pole is located at such a position that the plasmon generator is interposed between the magnetic pole and the waveguide; and the outer surface of the plasmon generator further includes a pole contact surface that is in contact with the magnetic pole.