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

Abstract

We present experimental results of our volumetric optical data storage system. To achieve volumetric recording over a wide depth range of 250 m 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. #

New Wobble-Address Format for an Optical Disc with a Separated Guide Layer

“…[2][3][4][5] Several technologies of realizing large-capacity optical storage have been reported, such as a volume holographic memory, [6][7][8][9] a solidimmersion objective lens system, [10][11][12] a multilayer disc system, [13][14][15] and others. [16][17][18][19][20][21][22] Multilayer technology for optical discs with a separated guide layer has been reported 23) as one of the most promising approaches for storing large-capacity data in a single disc. In this method, servo information is separately prepared in the guide layer away from the stacked recording layers.…”

Impact of Band Structure and Absorber Dynamics on Self-Q-Switching in GaN-Based Multisection Laser Diodes at High Reverse Bias

“…idge waveguide laser diodes with integrated saturable absorbers are compact and thus convenient sources of short-pulse laser light. In the violet-blue spectral region, potential applications, e.g., high-density optical storage systems, [1][2][3] optical coherence tomography, 4) and ultraprecise nanoprocessing, 5) draw considerable attention worldwide. Within the group-III nitride material system, we can realize such devices by defining electrically isolated p-contact sections directly on the ridge waveguide of a conventional Fabry-Pe ´rot laser diode.…”

Volumetric Optical Recording Using a 400 nm All-Semiconductor Picosecond Laser

“…8,9) Using this recording method, we have recently demonstrated 34-layer (corresponding to a capacity of 200 GB) recording. 10,11) However, we used a picosecond titanium:sapphire (Ti:S) laser with a second-harmonicgeneration unit. This system is expensive and extremely large so that its usage is limited to research laboratories.…”

“…Although not demonstrated in this paper, this wide depth range coverage enabled us to record 34 layers to achieve a capacity of 200 GB. 11) The recording medium is composed of a cover layer, an organic material that functions as the void-formation (recording) layer, and a glass substrate; these layers are 50, 100, and 1200 m thick, respectively (see Fig. 3).…”