| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical information recording medium capable of giving a signal having a sufficient modulation degree even if reproduction is carried out using a reproducing device with laser light for reproduction having two different wavelengths. SOLUTION: The optical information recording medium capable of reproduction with 1st laser light having a 1st wavelength λ1 and 2nd laser light having a 2nd wavelength λ2 has an information recording region 102 with pit parts and land parts on one side, transparent substrates 101, 105 having a refractive index n1 at the wavelength λ1, a reflecting layer 103 formed in such a film thickness as to saturate the reflectance to the 1st laser light 107 and the 2nd laser light 108 and a transparent medium 104 having a refractive index n2 at the wavelength λ2. The pit parts are formed in such a depth as to obtain the maximum amplitude when the information recording region 102 is reproduced with a 1st reproduction beam from the transparent substrate side and the relation among λ1, λ2, n1 and n2 satisfies the expression 0.75<=(n1×λ2)/(n2×λ1)<=1.25. |
