JP2734664B

PURPOSE:To realize optical recording with using a cheap and harmless material by using a polymer substrate comprising a polymer material having large optical anisotropy in which grooves are formed under condition of large residual stress and then depositing a metal film having high absorptivity of light on the substrate. CONSTITUTION:The polycarbonate substrate 1 has grooves 3 for signal tracking formed by injection molding, and a Ti reflecting film 2 is formed on the substrate 1 by sputtering. When recording is performed on a disk of this constitution with semiconductor laser light of 830 nm wavelength, retardation of a recorded area changes from 100 nm to 50 nm by laser light of 10 mW power for 10 msec. Information can be written or read out by using changes in double refraction of the polycarbonate substrate 1. Thereby, optical recording can be performed in such a material harmless and cheaper than conventional one.