OPTICAL RECORDING REPRODUCING OPTICAL SYSTEM AND OPTICAL INFORMATION RECORDING AND REPRODUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To significantly increase the recording density for optical information recording and reproducing than a conventional method. SOLUTION: In the optical recording and reproducing optical system to converge the incident light for recording or reproducing information to project the light spot on the recording face of an optical recording medium, a material having >=1.5 cm-1 optical transmission loss coefficient for light at 200 to 375 nm wavelength is used as the material for the optical device constituting the optical recording and reproducing optical system.