Patent ID: 8614932

Claim:
A thermally-assisted magnetic recording head comprising: a medium facing surface that faces a recording medium; a coil that produces a magnetic field corresponding to data to be written on the recording medium; a main pole having a first end face located in the medium facing surface, the main pole allowing a magnetic flux that corresponds to the magnetic field produced by the coil to pass, and producing a write magnetic field for writing the data on the recording medium by means of a perpendicular magnetic recording system; a shield made of a magnetic material and having a second end face located in the medium facing surface; a return path section made of a magnetic material, the return path section allowing the magnetic flux that corresponds to the magnetic field produced by the coil to pass, and connecting the main pole and the shield to each other so that a space through which part of the coil passes is defined by the main pole, the shield, and the return path section; a waveguide including a core through which light propagates, and a cladding disposed around the core, the core having a front end face facing toward the medium facing surface; and a plasmon generator having a near-field light generating part located in the medium facing surface, the plasmon generator being configured so that a surface plasmon is excited on the plasmon generator based on the light propagating through the core, and the near-field light generating part generates near-field light based on the surface plasmon, wherein: the first end face and the second end face are located at positions that are different from each other in a direction of travel of the recording medium; the near-field light generating part is located between the first end face and the second end face; the front end face of the core has a first end portion and a second end portion that are located at opposite ends in the direction of travel of the recording medium, and the first end portion is located closer to the near-field light generating part than is the second end portion; and when the front end face of the core is divided into two regions: a first region extending from a midpoint position between the first end portion and the second end portion to the first end portion; and a second region extending from the midpoint position to the second end portion, one of the main pole and the shield overlaps only the first region of the front end face of the core when viewed in a direction perpendicular to the medium facing surface.