| 摘要 |
PURPOSE:To provide DRAW type CD which has a high modulation degree and high recording density and with which good track error signals are obtainable. CONSTITUTION:A light absorption layer 2 is provided directly or via other layer on a substrate 1 on the front surface of which information pits and/or guide grooves are previously formed. A light reflection layer is provided directly or via other layer thereon and further, a protective layer is provided thereon. The light absorption layer is so formed that the real number part (n) and virtual number part (k) of the double refractive indices thereof as well as the film thickness (d) of the light absorption layer satisfy relations 6<n.d/lambda<=1.2, k<=0.3. The information pits and/or guide grooves 3 are so formed that the film thickness of the light absorption layer 2 in the bottoms of the pits or grooves and the film thickness of the light absorption layer 2 in the land parts 4 thereof are approximately equal to each other. |
