OPTICAL RECORDING MEDIUM, OPTICAL RECORDING/REPRODUCING APPARATUS, OPTICAL RECORDING APPARATUS AND OPTICAL REPRODUCING APPARATUS, DATA RECORDING/REPRODUCING METHOD FOR OPTICAL RECORDING MEDIUM, AND DATA RECORDING METHOD AND DATA REPRODUCING METHOD

摘要

An optical recording medium (10) comprises a support substrate (11), a light-transmitting layer (12), a first dielectric layer (31) interposed between the light-transmitting layer (12) and the support substrate (11), a noble metal oxide layer (23), a second dielectric layer (32), a light-absorbing layer (22), a third dielectric layer (33), and a reflecting layer (21). Data is recorded/reproduced when a laser beam (40) is applied to the light-transmitting layer (12) side. The value lambda/NA is set to 640 nm or less where lambda is the wavelength of the laser beam (40) and NA is the numerical aperture of the objective lens. A condition Pwx0.1<=Pr<=Pwx 0.5 is set where Pw and Pr are the recording power and the reproducing power of the laser beam (40). Thus, a recording mark sequence including a recoding mark having a length of lambda/4NA or less is recorded and data is reproduced from the recoding mark sequence.