Thermodynamic simulation of magnetic-field-modulation methods for pulsed laser irradiation in magneto-optical disks.

Direct overwrite magnetic-field modulation recording with dc and pulsed laser irradiation in a magneto-optical disk was simulated thermodynamically. Because the laser light heats the magnetic film, which allows the magnetization to be reversed, the waveform of the laser light strongly affects the shape of the magnetic domain. The dynamic temperature changes in magnetic thin films are simulated for dc and pulsed laser irradiations. With pulsed irradiation the heat is constrained within a limited area, which results in jitter-free magnetic domains, high optical efficiency, and high tracks-per-inch and bits-per-inch recordings.