Sixteen-Layer Write Once Disc with a Separated Guide Layer

Abstract

We proposed a new recordable multilayer optical disc and its recording system. The new optical disc has multiple-plane-recordable layers and a separated guide layer, and we fabricated 16 recording layers made of high-transmittance inorganic recording materials stacked on the separated guide layer. The recorded signals were evaluated on all recording layers by using jitter and i-MLSE as the evaluation indicators. As a result, the technical feasibility of our proposal was confirmed to achieve the total capacities of 400 and 512 Gbytes, respectively, by the continuous recording of all 16 recording layers with a track pitch of 0.32 µm and two bit lengths. We believe that our multilayer optical disc and recording system are the most practical solutions for realizing huge-capacity data storage.

Advanced Radial Position Control of a Recording Beam for Super Multilayer Disc with Separated Guide Layer

“…To lighten the manufacturing burden, we have already proposed the separated guide layer concept to simplify the disc structure and confirmed the technical feasibility of realizing the recording capacity of 512 GB. 21,22) In this paper, we introduced the advanced radial position control system for a super multilayer disc with the separated guide layer, which consists of an advanced sled servo system and a specially designed APP optics. We confirmed that the proposed system realized stable recording on the plane recording layer located far from the guide layer, with a constant track pitch of 0.32 m, the same as that of BD discs.…”

“…To lighten the manufacturing burden, we proposed the separated guide layer concept to simplify the disc structure and confirmed the technical feasibility to realize a recording capacity of 512 GB. 21,22) In our multilayer recording system, the radial position of a recording beam on the plane recording layer is controlled by using another one on the separated guide layer, called a guide beam. Therefore, there is a concern that the recorded track pitch will deviate owing to the difference in optical axis between the two laser beams.…”

Twenty-Layer Optical Disc Fabricated by Web Coating and Lamination

“…In recent years, this type of disc and system, i.e., the separated guide groove system, has been proposed. 5,25) Our multilayer disc is supposed to be used in such a system.…”

“…Several studies on the technology of high-capacity optical discs, for example, multilayer optical discs, [1][2][3][4][5][6] holographic memories, 7,8) solid immersion lenses, 9,10) superresolution near-field structures (super-RENS), 11,12) and flexible discs, 13,14) have been reported. In particular, the multilayer optical disc is the most promising technology for realizing high-capacity storage devices because it can utilize Blu-ray disc (BD) technology for its basic system.…”

“…In particular, the multilayer optical disc is the most promising technology for realizing high-capacity storage devices because it can utilize Blu-ray disc (BD) technology for its basic system. Many studies of super-multilayer discs that have 10 or more recording layers [4][5][6] have also been reported. These studies provide important ideas regarding super-multilayer discs, for example, the use of alternative spacer thickness and separated guide groove structures.…”