Patent ID: 8077556

Claim:
A thermally assisted magnetic head comprising: a medium-facing surface facing a magnetic recording medium; a near-field light generator provided on a light exit face in the medium-facing surface; a magnetic recording element located adjacent to the near-field light generator; a light emitting element provided so that emitted light thereof reaches the near-field light generator; and a core of a planar waveguide including the light exit face where the near-field light generator is formed, wherein the near-field light generator is a plate-like member that extends along the medium-facing surface and is comprised of a cusp portion formed from a first material (a) and a base portion formed from a second material (b) as viewed from the medium-facing surface, wherein the emitted light from the light emitting element is incident to a light entrance face of the planar waveguide, wherein when λin is a wavelength of the emitted light from the light emitting element immediately before the emitted light reaches the near-field light generator, an intensity of near-field light generated when the first material (a) is irradiated with the light of the wavelength λin is larger than an intensity of near-field light generated when the second material (b) is irradiated with the light of the wavelength λin, wherein when λin is 350-420 nm, a combination (a, b) of the material (a) with the material (b) is one selected from the group consisting of the following combinations: (Al, Ag), (Al, Rh), (Al, Ru), and (Al, Pt), wherein when λin is 500-560 nm, the combination (a, b) of the material (a) with the material (b) is one selected from the group consisting of the following combinations: (Ag, Al), (Ag, Au), (Au, Al), (Au, Ru), (Au, Pt), (Au, In), (Au, Rh), (Ag, In), (Ag, Rh), (Ag, Ru), (Ag, Pt), (Au, Pd), (AuCu, Pt), (AuCu, In), (AuCu, Al), (AuCu, Pd), and (AuCu, Rh), and wherein when λin is 620-700 nm, the combination (a, b) of the material (a) with the material (b) is one selected from the group consisting of the following combinations: (Au, Ag), (Au, Al) and (Au, Rh).