| 摘要 |
PURPOSE:To form the optical recording medium which is hardly flawed and corroded, is strong to repetitive reproduction and is light in weight by changing the refractive index of an optical recording layer at the wavelength of reproducing light equal to the wavelength of recording light before and after the irradiation of the recording light. CONSTITUTION:The optical recording layer 2 having the low light absorbability in the specific wavelength region and a reflecting layer 3 are provided on a transparent substrate 1. The reflecting layer 3 reflects the reproducing light at a high reflectivity, for which gold, platinum, Al, etc., are used. The refractive index of the recording layer 2 at the wavelength of the reproducing light equal to the wavelength of the recording light changes before and after the irradiation of the recording light and with such medium, the recording layer 2 is irradiated and condensed with the recording light of the wavelength at which the recording layer 2 exhibits the low light absorbability from the side of the substrate 1, by which refractive index changing parts 5 are formed in the recording layer 2 and signals are thus recorded thereon. Reproducing is executed by detecting the signals recorded on the recording layer 2 as the refractive index changing parts 5 by the reproducing light of the wavelength equal to the wavelength of the recording light and small energy. |
