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 mum 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.