Optical information recording medium, method for producing the same, and method and apparatus for recording/reproducing information thereon

An optical information recording medium comprising a first information layer, a separating layer, a second information layer and a protective substrate in this order on a transparent substrate, wherein

• the second information layer comprises an optical interference layer, a lower protective layer, a recording layer that changes between two different states detectable optically by irradiation of light beams, an upper protective layer, and a reflective layer whose refractive index is at least 2.5 at a wavelength λ of light beams used for recording in this order from a side near the transparent substrate,
• the optical interference layer comprises a first optical interference layer and a second optical interference layer in this order from a side near the transparent substrate,
• a refractive index of the second optical interference layer at the wavelength λ is smaller than that of the first optical interference layer and is smaller than that of the lower protective layer,
• an extinction coefficient of the first optical interference layer and an extinction coefficient of the second optical interference layer are both not more than 1, and
• a reflectance of the second information layer with respect to the light beams used for recording incident from the transparent substrate side after recording is higher than that before recording.