Patent ID: 8400887

Claim:
A thermally assisted recording magnetic head, comprising: a main pole that generates a write magnetic field; an auxiliary magnetic pole; a magnetic read element; a shield formed around the magnetic read element; and a spot size converter, including: a clad, an optical waveguide core that guides light from an optical source as a fine light spot to a position adjacent to the main pole on an air bearing surface side, wherein the spot size converter has a multi-mode-thin-film-like core that guides the light from the optical source into the magnetic head, and a cover layer having a refractive index lower than that of the clad is formed on an outer periphery of the optical waveguide core; wherein the optical waveguide core has a first portion, wherein width and thickness do not substantially change in a light traveling direction, and a second portion, that is tapered, wherein at least one of width and thickness is increased in the light traveling direction.