| 摘要 |
PURPOSE:To obtain excellent photosensitivity and reliability by using specific ceramics having proper values of heat resistance, coefft. of thermal diffusion and refractive index as a protective layer. CONSTITUTION:On the substrate 21, a first protective layer 22, medium layer 23, second protective layer 24 and a surface protective layer 25 are formed. The first and second protective layers 22, 24 are composed of such ceramics having a composition of (SiOx)1-y(Z)y, wherein Z is one of Cu, Al, Ti, Pt, Cr, Fe, Nd, Sm and Dy. By this constitution, the refractive indices and coeffts. of thermal diffusion of the protective layers 22, 24 become proper to increase the light absorptivity of the medium layer 23 in the optical recording medium. The energy of light can be effectively used for heating the medium layer 23 and the thermal diffusion of energy can be prevented. Thus, recording/erasing of informations can be performed with smaller laser power, while the reliability of the medium is improved. |
