| 摘要 |
PURPOSE:To enable multi-value theoretical recording by forming a photochromic recording layer of a diarylethene deriv. changing over from a specified state to other specified state when it reacts with light having a specified wavelength. CONSTITUTION:A photochromic recording layer of a diarylethene deriv. is formed. This deriv. changes over from a first state having a first absorption wavelength region to a second state having a second absorption wavelength region when it reacts with light having a first wavelength, changes over from the second state to the first state when it reacts with light having a second wavelength in the second absorption wavelength region, changes over from the first state to a third state having a third absorption wavelength region when it reacts with light having a third wavelength and changes over from the third state to the first state when it reacts with light having a fourth wavelength in the third absorption wavelength region. Three-value theoretical recording is enabled. |
