Optical information storage medium

摘要

An optical information storage medium comprising a transparent substrate and an information carrying layer positioned on one side of the substrate, wherein the information carrying layer contains at least 30 percent by volume of tin and at least 20 percent by volume of nickel oxide. The information carrying layer may be formed directly on one surface of the substrate. Alternatively, the information storage medium may further comprise a first spacer layer formed on one surface of the substrate and a second spacer layer which intervenes between the first spacer layer and the information carrying layer, wherein the first spacer layer is substantially transparent to a radiation with a predetermined wavelength and is larger in refractive index than the substrate at the aforesaid wavelength and the second spacer layer is substantially transparent to the aforesaid radiation and is smaller in refractive index than the first spacer layer at the aforesaid wavelength.