Magneto-optical disk properties enhanced by a nonmagnetic mask layer

Abstract

Magneto-optical (MO) recording signals were enhanced by a nonmagnetic mask layer combining a silver oxide (AgOx) thin film and near-field coupled super-resolution. The signal intensity of 300 nm marks recorded by a 680 nm laser and a lens numerical aperture of 0.55 with light-intensity modulation was amplified 100 times in comparison with conventional MO media. Resolution of less than 200 nm was achieved by near-field coupling between a light-scattering center generated in the AgOx film and light polarization of MO marks. To identify near-field enhancement, we simulated electrical field components, finding that near-field coupling between the light-scattering center and a MO layer enhances MO signals about 20 times due to the surface plasmon effect.