OPTICAL INFORMATION RECORDING MEDIUM, METHOD FOR PRODUCING THE DAME, AND METHOD AND APPARATUS FOR RECORDING/REPRODUCING INFORMATION THEREON

摘要

PURPOSE: Provided is an optical information recording medium having high S/N(signal to noise) ratio, high erasing rate and low cross erasing in the overwrite. CONSTITUTION: The optical information recording medium comprises a first information layer(2), a separating layer(3), a second information layer(4) and a protective substrate(5) in this order on a transparent substrate. The second information layer includes an optical interference layer(6), a lower protective layer(7), a recording layer(8), an upper protective layer(9), and a reflective layer(10) in this order from the side near the transparent substrate. The reflective layer has a refractive index of at least 2.5 at a wavelength(λ) of light beams(11). The second information layer is a reflective-increase type where the reflectance with respect to the light beams incident from the transparent substrate side after recording is higher than that before recording. It is possible not to provide the optical interference layer(6) if the ratio n1/n2 of the refractive index(n1) at the wavelength(λ) of the recording layer before recording to the refractive index(n2) thereof after recording is not more than 0.8.