Superresolution near-field readout in phase-change optical disk data storage

Abstract

Readout of a phase-change optical disk with a superresolution (SR) near-field structure (Super-RENS) is theoretically examined on the basis of three-dimensional, full-wave vector diffraction theory. Calculations have demonstrated that Super-RENS has a high spatial resolution beyond the diffraction limit in readout. The read signal is dependent on the nature of SR, the layer structure of the disk, and the state of polarization of the incident laser beam. For the Super-RENS in which antimony is used for SR readout, the readout signal is quite small, and the estimated carrier-to-noise ratio (CNR) is only ~30 dB for marks of 300 nm. For the Super-RENS in which a metallic region is formed during readout, the read signal is large, and the CNR can be as high as 50 dB in reading 300-nm marks.

Super-resolution near-field imaging on microfluidic structure

“…Fig3 (a) shows the electric field intensity distribution through the "nano-aperture" formed in Sb layer; (b) shows the near-field distribution through the "nano-aperture" formed in AgOx layer. The results agree with the reference [4] .…”

“…The layer structure and the reflective index of each layer are shown in Fig1 (b). All the parameters come from the reference [4] .…”

Feasibility of Cu/a-Si Bilayer for High Data-Transfer-Rate Write-Once Blue-Ray Recording

“…If the thermal and shot noises in the readout channel are negligible, the CNR is theoretically proportional to ðÁR=RÞ 2 . 10,11) To achieve a CNR greater than 45 dB, ÁR=R is required to be higher than 6%. Apparently, the Cu/a-Si bilayer has a sufficient optical contrast for blue laser recording.…”

Plasmonic data storage medium with metallic nano-aperture array embedded in dielectric material

“…When the incident power is sufficiently large, the thermal and the shot noises are negligible [27]. In the typical conditions, a linear relationship between the CNR and the contrast of signal is well established [28] and we estimate the CNR in the present form of the medium to be 30 dB. We expect that the CNR can be improved to meet the specification (45dB) for commercial data storage devices by subtracting floating background signal caused by the reflection at the front surface of the metal film.…”