WAVELENGTH MULTIPLEX OPTICAL RECORDING MEDIUM

摘要

PURPOSE:To eliminate thermal interference between recording layers and to suppress crosstalks (interference) to a low level by providing transparent heat insulating layers between plural optical recording layers of which the respective layers are subjected to recording selectively to light of different wavelengths. CONSTITUTION:Replica layers 12 are formed on a disk-shaped substrate 1 and the optical recording layers 21-23 are laminated alternately with the transparent heat insulating layers 4 thereon. A reflection layer 3 is provided thereon as the final stage of the lamination. The length (l) over the entire part of the laminated recording films is preferably smaller than the focal depth of a throttled laser 5. The light beams of wavelengths lambda1-lambda3 are respectively absorbed in the recording layers 21-23 but the heat generated by the absorbed recording light pulses is prevented from being diffused to the adjacent recording layers by the transparent heat insulating layers 4. The crosstalks occurring in the thermal diffusion between the recording layers are thus decreased.