Patent ID: 8526293
Filing Date: 2013-09-03
Classification: G11B

Abstract:
1. An information recording medium comprising: an information layer including a recording layer capable of changing a phase containing at least one selected from germanium-tellurium (Ge—Te), antimony-tellurium (Sb—Te) and germanium-antimony (Ge—Sb), and two or more dielectric layers disposed on an optical beam incident side with respect to the recording layer; and a transparent layer being disposed adjacent to the information layer on the optical beam incident side with respect to the information layer, being made of a transparent material with respect to the optical beam, and having a refractive index n of 1.75 or more, wherein the dielectric layers include a dielectric layer b disposed adjacent to the transparent layer and a dielectric layer a disposed adjacent to the dielectric layer b, the refractive index n of the transparent layer, a refractive index n the transparent layer contains an acrylic resin, and the information recording medium is capable of recording or reproducing information via an optical system having a numerical aperture (NA) >1 by irradiation with an optical beam.