Sub-Terabyte-Data-Capacity Optical Discs Realized by Three-Dimensional Pit Selection

Abstract

To realize optical discs with the sub-terabyte data capacity, we propose the three-dimensional pit selection (3DPS) method where a single data pit to be read out in a multi-layer disc is selected three-dimensionally to obtain super-resolution in the disc plane and to reduce layer cross-talk. To examine the feasibility of this method, the phase-change pit capsule method was tested where the data pits consist of a phase-change material which melts during readout. The super-resolution effect was observed for both layers of a dual-layer disc. It was shown that a quadric-layer disc can be designed because of the high transmittance of each layer. Thus, 3DPS is considered to have the potential for a data capacity of hundreds of gigabytes with a conventional optical system.

Demonstration of readout-signal quality improvement by homodyne detection

“…The estimated amplification of signal amplitude was 13 times. From these results, we believe that the homodyne detection technique is essential for fully utilizing the huge capacity of multilayer optical discs and is also applicable to other optical memory technologies such as microhologram [13], near field recording [14], and super resolution [15].…”

Demonstration of readout-signal quality improvement by homodyne detection

“…The estimated amplification of signal amplitude was 13 times. From these results, we believe that the homodyne detection technique is essential for fully utilizing the huge capacity of multilayer optical discs and is also applicable to other optical memory technologies such as microhologram [7], near field recording [8], and super resolution [9].…”

Fabrication of Discs for Three-Dimensional Pit Selection Using Damascene Process

“…These experimental results prove that damascene discs produce a super-resolution effect similar to that described in the literature. [4][5][6] Sputtering Sputtering…”

“…Various techniques for next-generation optical recording systems have been proposed to achieve data capacities of about 200 Gbytes or more. [1][2][3] A multilayer super-resolution technique called three-dimensional pit selection (3DPS) 4,5) has been proposed to achieve these systems. We demonstrated a super-resolution effect with a dual-layer disc, which has data pits consisting of s phase-change material that was fabricated by phase-change etching.…”