Effect of FePt on resonant behaviour of a near field transducer for high areal density heat assisted magnetic recording

This paper presents an experimental study of the effect of magnetic media on the resonant behavior of nano-apertures which are used as near-field transducers in near-field applications. Transmission spectra through C-shaped nano-apertures with and without a magnetic medium in the near-field were measured. A significant shift in the resonant wavelength of the C-apertures was predicted by simulations and subsequently observed experimentally. The resonant wavelength shift depends on the thickness of the magnetic medium and starts to saturate as the magnetic medium becomes thicker. Near-field intensity simulations illustrate dimensional parameter requirements for C-aperture design when a magnetic storage medium is placed within the near field.