Patent ID: 8644126

Claim:
An optical information recording medium comprising: a plurality of recording layers, each of which undergoes a change in a refractive index by irradiation with a recording beam; and at least one intermediate layer, wherein the intermediate layer is a composite layer including a first intermediate layer and a second intermediate layer, and is located between two adjacent recording layers, wherein the first intermediate layer is disposed adjacent to one of the two recording layers at a side opposite to an incident side from which a recording beam enters the recording layer, and a refractive index of the first intermediate layer is different from a refractive index of the recording layer both before and after information is recorded in the recording medium, wherein the second intermediate layer is disposed adjacent to the other one of the two recording layers at an incident side from which the recording beam enters the recording layer, and a refractive index of the second intermediate layer is substantially the same as that of the recording layer, and wherein the first intermediate layer and the second intermediate layer have different refractive indices from each other and are merged with each other at an interface therebetween, whereby a refractive index gradually changes at the interface.