| 摘要 |
PROBLEM TO BE SOLVED: To easily and surely prevent the reflection of light at an interface regardlessly of material of a layer forming the interface by constructing an optical recording medium consisting of a multi-layered structure provided with a transparent substrate and a recording layer, and forming an antireflection structure on a surface of the transparent substrate or on at least one interface of each layer. SOLUTION: A hologram memory 1 as an optical recording medium is constituted of a recording layer 2 interposed by two sheet of transparent substrates 3 and 4. Each interface between the transparent substrates 3 and 4 and the recording layer 2 and each surface (interface between air and the transparent substrate 3 and 4) has each antireflection structure 5, 6, 7 and 8 formed by an integral forming as antireflection treatment. For example the antireflection structure 6 has a grid structure in which circular groove parts and circular higher parts concentric with the center of the transparent substrate 4 are alternately arranged at a prescribed period. The arranged period of ruggedness is specified to be one fourth of a wavelength of incident light or less, preferably one tenth of that or less, and an optical height for which a rugged part is effective is specified to be one fourth of the wavelength of the incident light (or an odd number times the value). |
