Optical recording method

An optical information recording medium comprises: (a) a substrate; and (b) a phase-change recording layer (B) containing a crystalline part as an unrecorded/erased state and an amorphous part as a recorded state. Information is recorded by using recording marks whose shortest length is at most 0.5 mu m. Either (1) erasure is effected by recrystallization substantially progressed by the growth of crystals from the boundary between the amorphous part or a fused part and the peripheral crystal part; or (2) (B) comprises a thin film with main components of germanium (Ge), antimony (Sb) and tellurium (Te), and at a fixed line speed, the recording layer is irradiated continuously with recording light of sufficient power (Pw) to melt the recording layer and generally recrystallize it and then this is interrupted and amorphous marks formed; or (3) on the substrate, in order from the recording regeneration light irradiation direction, are provided a first protective layer, the layer (B), a 5-30 nm thick second protective layer, and a reflecting layer, the thickness of (B) is 5-25 nm, and (B) is a thin film comprising a main component of a germanium- antimony-tellurium (GeSbTe) alloy having a composition shown by the region enclosed by 4 lines, A, B, C and D (excluding the boundary lines), where A is the line joining (Sb 0.7Te 0.3) and Ge, B is the line joining (Ge 0.03Sb 0.68Te 0.29) and (Sb 0.95Ge 0.05), C is the line joining (Sb 0.9Ge 0.1) and (Te 0.9Ge 0.1), and D is the line joining (Sb 0.8Te 0.2) and Ge.