Opto-Thermal Analysis of Novel Heat Assisted Magnetic Recording Media Based on Surface Plasmon Enhancement

Novel media structure based on metal/dielectric layer for the surface plasmon enhancement was designed and analyzed opto-thermally to understand the effectiveness of local heating in the magnetic media for heat assisted magnetic recording (HAMR) application. Near-field optical and thermal characteristics of this surface plasmon assisted HAMR (SPAH) media were studied with a nano-slit aperture of grating HAMR head using finite differential time domain (FDTD) method and finite volume method (FVM). From FDTD simulation results, it was confirmed that the near-field transmitted light from nano-slit aperture of HAMR head is coupled strongly with the metal/dielectric interface of SPAH media to excite the surface plasmon waves. To compare the generated heat in SPAH media with conventional continuous media, FDTD data were converted to the poynting vector to calculate thermal distribution in both media. The transmitted power of 45 mW from the head resulted in the temperature of 575 K in the recording layer with 2 ns duration time at the SPAH media while same condition showed 429 K at the continuous media. Since thermal efficiency of SPAH media is around 2 times better than that of continuous media, it is expected that the surface plasmon assisted HAMR media can be applied to the future high density magnetic recording.