Patent ID: 6426936
Filing Date: 2002-07-30
Classification: G11B

Abstract:
A product for recording information by use of a laser light, comprising:a recording layer configured to change between an amorphous state and a crystalline state so as to record information, said recording layer having a thickness falling within a first range defined relative to a wavelength of the laser light; a protection layer having a thickness falling within a second range defined relative to the wavelength of the laser light; a metal layer having a thickness falling within a third range defined relative to the wavelength of the laser light; and a transparent substrate supporting said recording, protection, and metal layers, wherein the first, second, and third ranges are selected such that a phase of the laser light reflected by the amorphous state and a phase of the laser light reflected by the crystalline state have a phase difference larger than a predetermined phase amount, and the first range is between 0.023 times the wavelength of the laser light and 0.033 times the wavelength of the laser light.