Patent ID: 8358565

Claim:
A thermally assisted magnetic recording head, comprising: a slider with an air bearing surface; and a light source unit comprising a light source formed on a light source supporting substrate; wherein the slider includes a slider substrate and a magnetic head part formed on a side surface position of the air bearing surface of the slider substrate; the magnetic head part includes a magnetic recording element part that generates a magnetic field for writing, a main waveguide for assistance for receiving light from a back end surface located on a side opposite to the air bearing surface and guiding the light in the direction of the air bearing surface, and a dummy waveguide component part provided in parallel to the main waveguide for assistance in order to align the light source and the waveguide; and the dummy waveguide component part includes a pair of waveguides having the same shape and dimensions including a first waveguide and a second waveguide that receive light from the back end surface positioned on the side opposite to the air bearing surface and guides the light toward the direction of the air bearing surface, wherein light emitting ends of the first waveguide and the second waveguide facing towards the air bearing surface have no shielding material, and are in a free condition so that the light intensity from the light emitting ends can be measured, the light generated by the light source of the light source unit is introduced respectively from back end part sides of the first waveguide and the second waveguide, and the light source can be temporarily aligned to a center position of an interval between the first waveguide and the second waveguide so that the intensity of the light emitted from the light emitting ends of the first waveguide and the second waveguide in the direction of the air bearing surface becomes the same.