Patent ID: 8000175
Filing Date: 2011-08-16
Classification: G11B

Abstract:
1. A thermally assisted magnetic head, comprising: a slider having a medium-facing surface; and a surface-emitting semiconductor laser, wherein said slider has: a slider substrate, on which part of said medium-facing surface is formed; and a magnetic head portion, on which another part of said medium-facing surface is formed, and which has a first surface in contact with a head stacking surface of said slider substrate and a second surface opposite said first surface, said magnetic head portion has: a main magnetic pole that generates a write magnetic field from an end face on the side of said medium-facing surface; an optical waveguide core extending along said first surface and having a light exit surface at said medium-facing surface; a diffraction grating, which is provided in said optical waveguide core or further towards said second surface than said optical waveguide core, and the refractive index of which varies periodically along a direction in which said optical waveguide core extends; and an overcoat layer provided between said surface-emitting semiconductor laser and said optical waveguide core, wherein said surface-emitting semiconductor laser is a photonic crystal surface-emitting semiconductor laser, said overcoat layer defines said second surface, the diffraction grating is arranged within one of said overcoat layer and said optical waveguide core so as not to be exposed to said second surface, said surface-emitting semiconductor laser is provided opposing said second surface so that emission light from the surface-emitting semiconductor laser is incident onto said diffraction grating, and said diffraction grating causes at least part of emission light from said surface-emitting semiconductor laser to be optically coupled to said optical waveguide core and said diffraction grating is a stack comprising multiple layers of a first reflective index layer and a second reflective index layer that are alternatively stacked along said direction in which said optical waveguide core extends, a reflective index of said first reflective index layer being greater than that of said second reflective index layer.