Thermal Footprint Measurements for Heat Assisted Magnetic Recording

A method for characterizing the thermal footprints generated by a heat-assisted magnetic recording (HAMR) head onto an HAMR medium is presented. It uses a static tester and has the advantage over traditional recording techniques of measuring an undistorted two-dimensional image of the temperature profile, highlighting the lower temperature background created in the medium. Two-dimensional temperature profiles obtained from different near-field transducer (NFT) designs are presented and shown to compare very well to expectations from optical/thermal modeling. Micromagnetic simulations are used to illustrate the benefits of reducing the lateral extent of the temperature background.