| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk wherein unevenness(fluctuation) of a reproducing signal can be made uniform in the write-once optical disk using an organic dye film as a recording layer. <P>SOLUTION: The optical disk 1 has pits (grooves containing the pits) formed with 80 to 170 nm width expressed in terms of half-value width in at least regions respectively having 23.3 to 23.8 mm radius and 57.9 to 58.0 mm radius from the center of the disk. The grooves are formed in the depth in the range wherein (n<SB>1</SB>-n<SB>2</SB>)×d<SB>1</SB>+n<SB>2</SB>×d<SB>2</SB>=(2m-1)×λ/4 is within ±15%, when the refractive index n<SB>1</SB>of a base material, the refractive index n<SB>2</SB>of the recording film, wavelength λ of light used for recording and reproducing information, the depth d<SB>1</SB>of the guide groove, the depth d<SB>2</SB>of the recording film positioned on the guide groove, and an integer m (m=1, 2, 3, 4...) are respectively defined. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
