Numerical investigation of a light delivery device using metal/insulator/metal with a 3D linear taper waveguide and an input grating for heat-assisted magnetic recording.

Heat-assisted magnetic recording (HAMR), a new technique to overcome the data-density limitation, uses a laser to temporarily heat a nanovolume of a recording medium. Thus, this paper proposes a light delivery device that uses the metal/insulator/metal waveguide with a three-dimensional linear taper, and a grating added for an input, for HAMR. Our structure was calculated by finite-element method simulation. By design, 830 nm of light was delivered into a 50 spot area with 63% coupling efficiency, and power intensity was enhanced 930 times. This achievement potential could be applied to the HAMR system in the future.