Method for recording information on super-resolution optical recording medium and super-resolution optical recording medium

Abstract

When a recording mark and a space, each having a size depending on a modulation code corresponding to information to be recorded, are formed in a super-resolution optical recording medium which has at least a substrate and a recording layer, a super-resolution layer, and a light transmitting layer on the substrate, a space shorter than at least the resolution limit of a reproducing optical system is formed so that the space has a crescent shape when plan view from top surface and a convex section when viewed in a direction normal to a track, thereby allowing high carrier-to-noise ratio (CNR) recording of information.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view schematically showing a super-resolution optical recording medium in accordance with an exemplary embodiment of the present invention;

FIG. 2 is a block diagram showing an information recording and reproducing apparatus for recording and reproducing information on and from the super-resolution optical recording medium;

FIG. 3 includes plan views schematically showing the shortest recording mark which is formed in a recording layer of the super-resolution optical recording medium;

FIG. 4 is a diagram showing a relationship between recording power and CNR of a 2T mark train which is recorded on a super-resolution optical recording medium of Example 1;

FIG. 5 is a cross-sectional diagram showing concave and convex of the 2T mark train; and

FIG. 6 is a diagram showing a plan-view AFM (atomic force microscope) image of 2T mark trains which are recorded on the super-resolution recording medium by the recording laser beam with various graduated recording power.

Claims

1. An information recording method for irradiating with a recording laser beam a super-resolution optical recording medium which has at least a substrate and a recording layer, a super-resolution layer, and a light transmitting layer on the substrate so that a recording mark and a space, each having a size depending on a modulation code corresponding to information to be recorded, are formed while at least a shortest mark and space corresponding to the modulation code have a size equal to or less than a resolution limit of a reproducing optical system and can be reproduced in the reproducing optical system, wherein the recording layer is made from a material capable of changing its optical constant and volume when irradiated with the recording laser beam, and is irradiated with the recording laser beam so that the space having the size equal to or less than the resolution limit has a crescent shape when plan view from top surface and a convex section when viewed in a direction normal to a track.

2. A super-resolution optical recording medium, comprising: at least a substrate, a recording layer, a super-resolution layer, and a light transmitting layer on the substrate; anda recording mark and a space, each having a size depending on a modulation code corresponding to information to be recorded, wherein at least a shortest mark and space corresponding to the modulation code is recorded so as to have a size equal to or less than a resolution limit of a reproducing optical system and so as to be reproduced in the reproducing optical system, whereinthe space having the length equal to or less than the resolution limit of the optical reproducing system is formed to have a crescent shape when plan view from top surface and a convex section when viewed in a direction normal to a track.