Nanocavity Induced Light Concentration for Energy Efficient Heat Assisted Magnetic Recording Media

TL;DR

This paper presents a nanocavity design that significantly enhances light absorption in ultrathin FePt layers, improving energy efficiency for heat assisted magnetic recording by optimizing a resonant Ag/SiO2/FePt structure.

Contribution

The study introduces a resonant nanocavity structure that boosts light absorption in ultrathin FePt layers, advancing HAMR technology efficiency.

Findings

Light reflection reduced by over 50% in optimized structure

Effective laser heating demonstrated via infrared imaging

Design scalable for thinner layers and shorter wavelengths

Abstract

Enhancing light absorption in the recording media layer can improve the energy efficiency and prolong the device lifetime in heat assisted magnetic recording (HAMR). In this work, we report the design and implementation of a resonant nanocavity structure to enhance the light-matter interaction within an ultrathin FePt layer. In a Ag/SiO2/FePt trilayer structure, the thickness of the dielectric SiO2 layer is systematically tuned to reach maximum light absorption at the wavelength of 830 nm. In the optimized structure, the light reflection is reduced by more than 50%. This results in effective laser heating of the FePt layer, as imaged by an infrared camera. The scheme is highly scalable for thinner FePt layers and shorter wavelengths to be used in future HAMR technologies.