OPTICAL RECORDING METHOD AND OPTICAL RECORDING MEDIUM

摘要

PURPOSE:To allow the easy execution of not only the writing and reading out of information but the erasing and rewriting thereof as well as utilizing martensite transformation. CONSTITUTION:The point to be recorded with information of the thin film which is formed as a base phase over the entire part is irradiated with a laser beam so that the cooling after heating is rapidly executed to transform only this point from the base phase to the martensite phase in the case of recording of the information. A change in light reflectively arises in a pat of the thin film in this way and, therefore, the recording of the information is executed. On the other hand, the point to be erased of the thin film is irradiated with the laser beam to locally heat the thin film to the As point or above in order to execute partial erasing. The martensite phase is converted to the base phase in this way. On the other hand, the entire part of the thin film is heated together with the substrate to the As point or above in the case of simultaneous erasure. All the regions which are locally converted to the martensite phase are transformed to the base phase and the entire part of the record is simultaneously erased.