US Patent 7876664 Optical recording medium

An optical recording medium including three or more recording layers is provided. The optical recording medium includes an L0 layer, an L1 layer, an L2 layer, and an L3 layer as the recording layers and first to third light transmitting spacer layers respectively arranged between the recording layers. A refractive index n3 of the third light transmitting spacer layer is set to satisfy n3<n1 with respect to a refractive index n1 of the first and second light transmitting spacer layers. Thus, an effect of crosstalk light during reproduction can be reduced.