Patent ID: 8125857

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 including a core and a clad, the core propagating light; and a plasmon generator, wherein: the core has an evanescent light generating surface that generates evanescent light based on the light propagated through the core; the plasmon generator has an outer surface including a propagation edge, and has a near-field light generating part lying at an end of the propagation edge and located in the medium facing surface, the propagation edge facing the evanescent light generating surface with a predetermined distance therebetween and extending in a direction perpendicular to the medium facing surface; the propagation edge is arc-shaped in a cross section parallel to the medium facing surface; a surface plasmon is excited on the propagation edge through coupling with the evanescent light generated from the evanescent light generating surface, the surface plasmon is propagated along the propagation edge to the near-field light generating part, and the near-field light generating part generates near-field light based on the surface plasmon; and the plasmon generator includes a shape changing portion in which a radius of curvature of the propagation edge in the cross section parallel to the medium facing surface continuously decreases with decreasing distance to the medium facing surface.