Transmitted signal detection of optical disks with a superresolution near-field structure

Abstract

We observed transmitted signals of phase change marks recorded in super-resolution near-field structure (super-RENS) disks under high speed disk rotation. The observed minimum mark size was 81 nm and the carrier to noise ratio was about 6 dB at a constant linear velocity of 4.8 m/s. The mark size was far beyond the diffraction limit of an optical pickup with a wavelength of 635 nm and a numerical aperture of 0.6. It was clear that near-field scattering actually occurred in super-RENS disks.