High Density Phase Change Optical Recording Using a Solid Immersion Lens

Abstract

The data density of the optical recording disk mainly depends on the light beam spot size. In conventional optical recording system, the beam spot size, which limited by the optical diffraction limit, can be reduced by using the shorter wavelength light source or larger NA objective lens. Recently, near-field optical techniques have been developed to overcome the defecation limit. In particular, Betzig et al.1) have applied the scanning near-field optical microscope (SNOM) optics, which has a tapered fiber prove with sub-micron aperture, for the recording of magneto-optical (MO) media. However. the low optical coupling efficiency of this fiber prove need a further improvement for practical data storage application. For another approach. Terris et al.2) have developed near-field optical recording optics using the solid immersion lens which has been developed as the optics for a microscope by Mansfield and Kino3). They have demonstrated recording of the 350 nm diameter mark on MO media by using the truncated spherical shaped SIL.