Abstract: In a phase change optical recording medium in which writing, reading and/or erasing of information is conducted by utilizing change of phase of a recording layer by irradiation with light, the recording layer is made of a material containing oxygen in an amount of 1 to 30 atomic %; or the recording medium comprises an additional transparent dielectric layer 1 to 10 nm thick between the recording layer and the underlying transparent dielectric layer and the inserted transparent dielectric layer in contact with the recording layer comprising oxygen in a molar ratio greater than a molar ratio of oxygen in the underlying transparent dielectric layer; or the transparent dielectric layer underlying and in contact with the recording layer comprises oxygen in a molar ratio greater than a molar ratio of oxygen in the other transparent dielectric layer.

Abstract: In a phase change optical recording medium in which writing, reading and/or erasing of information is conducted by utilizing change of phase of a recording layer by irradiation with light, the recording layer is made of a material containing oxygen in an amount of 1 to 30 atomic %; or the recording medium comprises an additional transparent dielectric layer 1 to 10 nm thick between the recording layer and the underlying transparent dielectric layer and the inserted transparent dielectric layer in contact with the recording layer comprising oxygen in a molar ratio greater than a molar ratio of oxygen in the underlying transparent dielectric layer; or the transparent dielectric layer underlying and in contact with the recording layer comprises oxygen in a molar ratio greater than a molar ratio of oxygen in the other transparent dielectric layer.

Abstract: A phase change optical recording medium in which writing, reading and/or erasing of information is conducted by utilizing change of phase of a recording layer by irradiation of a light beam, said recording medium comprising a substrate, a first transparent protecting layer of an amorphous dielectric material on the substrate, a recording layer of a chalcogen alloy on the first transparent protecting layer, an adhesive layer of a crystalline sulfide 10 to 30 nm thick on the second recording layer, a second transparent protecting layer of an amorphous dielectric material on the adhesive layer, and a reflection layer of a crystalline alloy mainly comprising aluminum on the adhesive layer.