| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical recording medium in which four-bits information can be read and written and the recording density can be improved. SOLUTION: The optical recording medium 6 has a recording region 2 comprising an optically active substance containing a pair of antipodes in a specified proportion. Information can be written in the medium 6 by subjecting the recording region to one of the processes of irradiating with nonpolarized light at the wavelength which induces the reaction including decomposition of the optically active substance, of irradiating with dextrorotatory circularly or elliptically polarized light which induces the reaction including decomposition of the optically active substance, of irradiating with levorotatory circularly or elliptically polarized light which induces the reaction including decomposition of the optically active substance, and of no irradiation. |
