OPTICAL INFORMATION RECORDING MEMBER

摘要

PURPOSE:To extend the life in repeating of recording and erasure by using boron nitride to constitute heat resistant protective layers to be provided on both sides of an optically active layer, the optical constant of which varies with temp. elevation by photoirradiation. CONSTITUTION:For example, an optical memory material of a phase change type consisting of Te-Ge-Sn-O or amorphous phase of a rare earth-transition metal alloy is used as the optically active layer 3 and the heat resistant protective layers 2, 4 are constituted of the boron nitride. The boron nitride has excellent heat resistance and the refractive index thereof is 2.13 and is larger than the refractive index of the base material; therefore, the boron nitride is superior to the conventional protective material in an overall point of view and is capable of stabilizing the optically active layer. The number of the repeating cycles of the recording and erasing is thereby increased and the reliability is improved.