FIELD: data media. SUBSTANCE: optical multilayer information medium has information layer of standard density and information layer of high density. First information layer is located on substrate, for instance, 1.2 mm thick and is read by laser beam through substrate. Second layer is formed from substance which is clear to laser radiation with length of wave characteristic of standard CD players ( λ=780 nm ) but reflects shorter wavelengths used for discs of high density ( λ=635 NM). Smaller unit of track and smaller recesses are used to achieve high density in second layer. Layer of high density is located close to side of entrance of laser beam into substrate. EFFECT: improved quality of reading signals as it is suffering less distortions while standard layer is read. 7 cl, 3 dwg
