Layer Stack Design of High Density Read-Only-Memory Discs for Near-Field Systems using a Solid Immersion Lens

Abstract

For high numerical aperture (NA) near-field systems using a solid immersion lens, layer stack types of first-surface read-only-memory (ROM) discs have been investigated. Complicated interactions of high-NA incident and diffracted waves with surface waves occur in multilayer-stacked subwavelength structures on the discs. Therefore, vector diffraction simulation in consideration of these effects is indispensable for the optimization of the disc structures. We used rigorous coupled wave analysis to numerically calculate readout signals from the discs. On the basis of the simulation results, we actually fabricated high-density ROM media. Consequently, a significantly low jitter of 6.8% was obtained for 100 Gbyte ROM media with a designed structure in an NA 2.0 system.

Recording characteristics of high-density thin optical disk using near-field optical recording

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] It can exhibit a large capacity and a highdata transfer rate towards recording next-generation ultrahigh-definition television [i.e., Super Hi-Vision (SHV), 7320 Â 4320 pixels] video signals 17,18) for home-use. Fourfold higher density recording using NFR optical disks with 1.2-mm-thick disks has been reported, 12,14) and studies of larger capacity using multilayer recording using NFR have been reported. 15,16) If the NFR media can realize 250-Mbpsclass high-speed recording and two-or three-layer recording, the SHV optical media, which has more than two hours recording ability would be able to be realized.…”

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

“…These days, many impressive results of technical candidates for the next-generation optical discs have been reported in this field. The technical candidates include volumetric storage technology, [1][2][3][4][5][6] near-field technology, [7][8][9][10][11][12][13] and multilayer technology, [14][15][16][17][18][19][20] which is a volumetric storage technology. Among them, multilayer technology has a lot of advantages such as storage capacity, backward compatibility, and system practicability, and so on.…”

Near-Field Optical Recording Using Solid Immersion Lens for High-Density Flexible Optical Disks

“…A near-field optical recording (NFR) system using a solid immersion lens (SIL) 1) has a fourfold higher recording density than the Blu-ray disc system. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Some studies have shown the realization of a large recording capacity using multilayer recording techniques for optical disks, [17][18][19][20][21] but the data transfer rate is limited. The NFR system is expected to realize not only a large capacity but also a high data transfer rate because its numerical aperture (NA) is more than two times higher and the optical beam spot can be less than half the diameter of current Blu-ray optical systems.…”