| 摘要 |
PROBLEM TO BE SOLVED: To improve the recording sensitivity, jitter and modulation degree for fast recording by controlling the spectrum of a dye in a dye film having a small film thickness per unit absorbance (unit absorbance thickness). SOLUTION: The average film thickness D (nm) of a light-absorbing layer, the max. absorbance C (Abs) by molecular absorption of the light-absorbing material, the max. absorbance B (Abs) by association absorption of the light- absorbing material, the unit absorbance thickness D/C by molecular absorption of the lightabsorbing material, and the unit absorbance thickness D/B by association absorption are controlled to satisfy 0<D/Cη100 and 80<=D/B. If D/C is larger than 100, the film thickness is too large compared to the max. absorbance C by molecular absorption and the medium does not satisfy the specification of modulation and jitter for recording and reproducing. If D/B is less than 80, the absorption peak in a shorter wavelength region is too large for the film thickness D, which makes recording with small laser power impossible. |
