OPTICAL RECORDING MEDIUM AND OPTICAL MEMORY DEVICE

摘要

An optical recording medium comprising a mask layer of which the refractive index of a part in a light spot formed by a laser beam 2 - 4 mW is changed and protective layers sandwiching the mask layer, wherein the difference between the intensity of reflected light in a crystalline state and the intensity of reflected light in an amorphous state is small in the region where the refractive index has changed and the reproduced signal is difficult to view in a region other than the region where the refractive index has changed. By reducing the size of the part where the reproduction signal is viewed, high density recorded information can be read.