| 摘要 |
PURPOSE:To reduce the written-in energy, by providing the substance layer having low boiling point or low decomposition temperature acting as the trigger for the pit formation on the base, and providing the pit forming layer with the metal having lower melting point than the boiling point of trigger substance. CONSTITUTION:A substance like phthalocyanine having good stability and easy vapor deposition is vapor-deposited to the glass substrate 2 to form the trigger layer 1. The metallic layer (low melting point alloy consisting mainly of Bi, Pb, Sn, In and In-SiO2 cermet film, etc.) 3 having lower melting point than the boiling point or decomposition temperature of trigger substance, is formed to make light storage medium. When the laser light beam is irradiated from the layer 3 and the fine part 4 of the layer 1 is vaporized, the layer 3 is molten and the pit 5 is formed in sufficient size for the desired readout. If no trigger layer 1 is present, the pit 5 can be formed with several tens % lower energy in comparison with the heating over the boiling point of the metallic layer 3. |
