Far-field head-media optical interaction in heat-assisted magnetic recording.

We have used a plane wave expansion method to theoretically study the far-field head-media optical interaction in heat-assisted magnetic recording. For the Advanced Storage Technology Consortium media stack specifically, we notice the outstanding sensitivity related to the interlayer's optical thickness for media reflection and the magnetic layer's light absorption. With 10 nm interlayer thickness change, the recording layer absorption can be changed by more than 25%.

Cutoff wavelength of ridge waveguide near field transducer for disk data storage.

The electromagnetic eigenmodes of and light transmission through a C-aperture to the far field, and to a storage medium, have been studied based on the full vectorial finite difference method. It is found that the cutoff wavelength of C-aperture waveguides in a gold film is much longer than that in a perfect electric conductor, and the fundamental mode is confined in the gap and polarized with the electric field along the gap. The light transmission resonance through C-apertures to far field and to a storage medium occurs at wavelengths below the waveguide cutoff wavelength.