Three-dimensional thermal modeling and analysis of near-field rewritable phase-change optical disks

Abstract

The data density of the optical recording disk is mainly dependent on the light beam spot size. In conventional optical recording system, the beam spot size, which is limited by the optical diffraction limit, can be reduced by using a shorter wavelength light source or objective lens with larger NA. Recently, near-field optical techniques have been developed to overcome the diffraction limit. In particular, Betzig et al have applied the scanning near-field optical microscope (SNOM) optics, which as a tapered fiber prove with sub-micron aperture, for use in the recording of magneto-optical (MO) media. However, the low optical coupling efficiency ofthis fiber prove need further improvement before it is practical for application in data storage. Terris et al have developed another near-field optical recording optics using the solid immersion lens that has been developed as the optics for a microscope by Mansfield and Kino. They have demonstrated the recording of the 350nm diameter mark on MO media by using the truncated spherical shaped Solid Immersion Lens (SIL).