Mask Films for Thermally Induced Superresolution Readout in Rewritable Phase-Change Optical Disks

Abstract

Tellurium was studied as a mask film in a thermally induced superresolution rewritable optical disk for detecting below-diffraction-limit marks. Mark trains of 0.15 µm could be retrieved with 9 dB in carrier-to-noise (CNR) using an optical system with the laser wavelength of 780 nm and an objective lens of 0.55 numerical aperture. Readout cyclability was examined and methods to further improve readout cyclability were proposed.

On a thermally induced readout mechanism in super-resolution optical disks

“…The recording conditions for GST were also identical, however, for the case of Si, the recording process was carried out with a P w of 13 mW, a pulse frequency of 7.5 MHz, and a LV of 3 m / s, which implies a mark length of 200 nm. Lu et al 16 reported a similar drop in CNR for a super-RENS disk fabricated with a Te mask layer. 7 for the GST case and For Si, we also measured the CNR at different LVs.…”

A Study of Material Selection for Super-Resolution Readout of Optical Disk with PtOx Recording Layer

“…This aperture overcomes the resolution limit of the optics used, and the readout of small marks beyond the limit (for higher recording density) becomes possible. The key to this super-resolution technique is the material used for aperture formation, and various materials, e.g., Ge 2 Sb 2 Te 5 , 1) Te, 2) Co 3 O 4 , 3) ZnO, 4) AlGe, 5) Sb, 6) AgO x , 7) Ag 6:0 In 4:5 Sb 60:8 -Te 28:7 , 8) Sb 3 Te, 9) and Ag 2 Te, 10) have been reported.…”