Patent ID: 8270261

Claim:
A thermally-assisted magnetic recording head comprising: a magnetic pole for generating write field from its end surface on an opposed-to-medium surface side; a waveguide through which a light for exciting surface plasmon propagates; and a near-field optical device configured to be coupled with the light in a surface plasmon mode and to emit near-field light from its near-field-light-generating end surface that forms a portion of the opposed-to-medium surface and is located adjacent to the end surface of the magnetic pole on the opposed-to-medium surface side, a cross-section of the waveguide having substantially a shape of a trapezoid in which a longer side of opposed sides parallel to each other is an edge of the cross-section on the near-field optical device side, in at least a portion of the waveguide that is opposed to or has a contact with the near-field optical device, the cross-section being taken by a plane perpendicular to an edge of the waveguide along its elongated direction.