Near-field optical coupling and enhancement in surface plasmon assisted media for heat assisted magnetic recording

As a new structure of heat assisted magnetic recording (HAMR) media, the "surface plasmon assisted HAMR (SPAH) media" was studied to increase the near-field optical power in magnetic media with the aid of the surface plasmon effect at the metal/dielectric interface. Since the near-field light penetrating a nano-slit aperture is coupled at the metal/dielectric interface of the SPAH media, surface plasmon polaritons are excited in the SPAH media, resulting in the enhancement of near-field optical power for HAMR applications. From finite differential time domain (FDTD) simulations, we found that the near-field optical intensity through the nano-slit aperture shows a value 5 times higher at the surface of SPAH media than that shown with conventional discrete track media. In addition, the spot size can be reduced by this near-field optical coupling in the SPAH media. The geometric variables of SPAH media as well as the tolerance of the head and media location were also studied to understand the optimum structure of SPAH media in consideration of the fabrication process.