PURPOSE: To obtain erasable recording and reproduction by utilizing the phase shift between crystalline silicon in a silicon layer and amorphous silicon.
CONSTITUTION: This recording medium is obtained by forming a layer of crystal silicon 12 as a recording medium on a circular substrate 11 of glass or silicon. When the crystalline silicon 12 is irradiated with beams such as an electron beam or ion beam, the irradiated part of the crystalline silicon is subjected to phase change into amorphous silicon 13. When polarized light is scanned, an information signal is read because of a difference in refractive index. When the amorphous silicon is irradiated wth laser light to obtain thermal energy, the amorphous silicon is subjected to phase change into the crystalline silicon reversely, erasing recording contents.
SAKANO SUSUMU
KOYABU KUNIO
