High density optical information recording medium using high refractive index layer

Abstract

Disclosed are an optical information recording medium for recording, reproducing and erasing information by emitting laser light with a wavelength in vacuum of .lambda., which has: a transparent substrate through which the laser light can be transmitted; a high refractive-index layer which is formed on the transparent substrate; a guide groove for tracking which is formed on the high refractive-index layer; and a recording layer which is formed on the guide groove for tracking; wherein a width W of the guide groove for tracking and a refractive index n.sub.a of the high refractive-index layer are so set that the following relation: W>.lambda./(2xn.sub.a) is obtained, and an optical information recording medium for reproducing information by emitting laser light with a wavelength in vacuum of .lambda., which has: a transparent substrate through which the laser light can be transmitted; a high refractive-index layer which is formed on the transparent substrate; a concave-convex pit which is formed on the high refractive-index layer; and a reflection layer which is formed on the concave-convex pit; wherein a width W.sub.p of the concave-convex pit and a refractive index n.sub.a of the high refractive-index layer are so set that the following relation: W.sub.p >.lambda./(2xn.sub.a) is obtained.

Dependencies are inferred from the claim text.