Study of Recorded Mark Width Change with Laser Power in Heat-Assisted Magnetic Recording

Abstract

The dependence of recorded mark width on laser power for heat-assisted magnetic recording is studied by experiment and simulation. In the experiment, with increasing laser power, the recorded mark width of perpendicular magnetic media increases, and the increase rate decreases and then increases. The simulations are carried out, and the results are compared with experimental results. It is shown that the experimental results are larger than the simulation results at both low and high laser powers. At low laser powers, it comes from the small thermal gradient in the central area of Gaussian-shaped thermal distribution. However, at high laser powers, it mainly results from the temperature dependence of the recording material's thermal conductivity. Simulation results indicate that, in a certain range of laser beam spot sizes, a small beam spot size will cause a larger recorded mark width at the same laser power.