Dynamic Recording of 200 Gbytes in Three-Dimensional Optical Disk by a 405 nm Wavelength Picosecond Laser

We present experimental results of our volumetric optical data storage system. To achieve volumetric recording over a wide depth range of 250 µm in a recording medium, we developed a relay lens system for compensating for the spherical aberration of a high-numerical-aperture (0.85) objective lens. The disk employs a single monolithic recording layer and a reference layer for servo control. A 405-nm-wavelength titanium:sapphire laser that exhibits 2 ps pulse duration and a more than 2 kW peak power is used for recording. We adopted void formation and mark position as recording principles. We have experimentally demonstrated 34-layer dynamic recording, corresponding to a capacity of 200 Gbytes.