OPTICAL RECORDING MEDIUM AND OPTICAL RECORDING SYSTEM

摘要

PROBLEM TO BE SOLVED: To make an optical recording medium low in wavelength dependency in the recording characteristic and suitable for high linear speed recording. SOLUTION: This optical recording medium has at least a recording layer based on organic dyes, a metallic reflection layer and a protection layer on a substrate where a guiding groove is preformed. This medium is made to have the compatibility between the shortest mark lengths recorded with the laser beam having the wavelength λ1 and that having the wavelength λ2 (0.40 μm<=λ1<λ2<=0.70 μm and 20 nm <=(λ1-λ2)<=30 nm) at the time of recording/ reproducing. The shortest mark length (EFM + modulation) is defined as a value of 0.30-0.45 λ/NA (wherein NA shows a numerical aperture and is 0.6-0.8; λshows a recording/reproducing wavelength and is 0.40-0.70 μm) and used when the random mark length recording is conducted.