Patent ID: 8406093

Claim:
A thermal-assisted-magnetic-recording head comprising: a magnetic main pole configured to generate a recording magnetic field; a magnetic return pole; a magnetic reproducing element; a shield formed around the magnetic reproducing element; and a light directing unit configured to emit light from a light source as a minute light spot from a location adjacent to the magnetic main pole near an air bearing surface, the light directing unit including: a light coupling unit configured to guide the light from the light source into a magnetic head, and a high-refractive-index core configured to couple with the light guided by the light coupling unit; and wherein the light coupling unit comprises a plurality of thin-film-like cores that have higher refractive index than the clad material and that are separated from each other by the clad material; and wherein the width, the thickness, or the refractive index of a thin-film-like core is selected so that the exudation of the propagating light is larger when the thin-film-like core is farther from the high-refractive-index core.