| abstract |
An optical information recording medium comprising a light transmitting substrate having a spiral pregroove formed on its surface, a light absorptive layer of a coloring matter formed on the substrate directly or with other layer interposed therebetween, and a light reflective layer made of a metal film formed on the light absorptive layer directly or with other layer interposed therebetween, wherein ΔS≦0.3 wherein ΔS is the optical phase difference represented by ΔS=2d sub {n sub -n abs (1-d abs /d sub )}/λ wherein d sub is the depth of the layer boundary on the substrate side of the light absorptive layer at the portion corresponding to the pregroove, d abs is the depth of the layer boundary on the light absorptive layer side of the light reflective layer at the portion corresponding to the pregroove, n sub is the real part of the complex refractive index of the substrate and any layer present on the substrate side of the light absorptive layer, n abs is the real part of the complex refractive index of the light absorptive layer, and λ is the wavelength of a laser beam. |