| 摘要 |
PURPOSE:To improve the stability of the recording part of a recording layer by radiating a light beam to the recording layer so as to cause the phase change of two different crystals to the radiated part, and detecting the difference of the optical characteristic between crystals so as to reduce the information. CONSTITUTION:A laser beam of a prescribed condition is radiated to a recording layer 3 via a base 1 or both the base 1 and a protection layer 2 to bring the entire crystal into a crystal of a form shown in figure (a). Then a laser beam of the different condition is radiated to cause the phase change to the crystal of a form shown in figure (b), thereby forming a recording pit of information. Moreover, the laser beam is radiated by a first condition to erase the information, a weak laser beam is radiated to the recording layer 3 to detect the reflectance thereby reproducing the information. Since the information is recorded and erased by the phase change between crystals the stability of the recorded information is improved. |
