Erasable phase change disks with super resolution capability by pulse-readout

Abstract

Erasable thermal phase change super resolution (EPSR) disks composed of mask and recording layers can be Fabricated with a "below-diffraction-limited": aperture within the readout spot to achieve optical super resolution. The formation of the aperture and the readout signal on the EPSR disk were analyzed. The feasibility of the designed EPSR disks was evaluated by thermal simulation. A carrier-to-noise-ratio (CNR) of 32 dB at mark size of 0.4 mu m, 8 dB higher than that in a conventional disk, was obtained by applying pulse-readout to the EPSR disks at a wavelength of 780 nm and numerical aperture of 0.55.