| 摘要 |
PURPOSE:To obtain a data recording medium capable of recording data by light and having high reflectivity by providing a dye recording layer characterized by that the value of the extinction coefficient being the imaginary number part of a complex refractive index is larger than the value obtained by adding 1 to the refractive index being the real number part thereof at the oscillation frequency of laser beam used in recording or reproduction. CONSTITUTION:The recording layer possible to write data by laser beam provided on a substrate is composed of a dye and satisfies formula (1) (wherein nr is the real number part of the complex refractive index of the recording layer at the oscillation wavelength of laser beam used in recording or reproduction and kr is the imaginary number part of the complex refractive index). The thickness of the recording layer is within the range of 50 - 200 nm and the dye is selected from a cyanine dye, an oxonol dye, a melocyanine dye, a pyrrilium dye, a thiopyrrilium dye and a heteroanulene dye and the absorption max. of the recording layer is within the wavelength range of 700 - 900 nm and the reflectivity thereof to laser beam on the side of the substrate is 50% or more. |
