Patent ID: 6671235
Filing Date: 2003-12-30
Classification: G11B

Abstract:
A track-writing apparatus for forming tracks with a track width TW and track spaces with a space width SW on a magnetic media disk having an upper surface and comprising a magnetic medium with a thermal diffusion length, the apparatus comprising, in order along an optical axis:a laser light source capable of providing a pulsed beam of laser light; an illumination shaping optical system that provides substantially uniform illumination over an exposure region; and a phase plate having a phase grating with a grating period p, arranged proximate and substantially parallel to the upper surface of the disk so as to form a periodic irradiance distribution at the surface of the disk when said phase plate is illuminated with said exposure region, said irradiance distribution capable of heating one or more regions of the disk to beyond the Curie temperature of the magnetic media.