Optically High Spatial Resolution Obtained Using Super-Resolution Near-Field Structure Disk System

Abstract

Super-resolution near-field structure (Super-RENS) disks with AgInSbTe (AIST) mask layers with varying thicknesses were prepared and their spatial resolutions were experimentally evaluated. The thickness of each AIST mask layer was changed from 6.5 to 18.6 nm. A Super-RENS disk with a mask layer thickness of 18.6 nm was recorded and retrieved at a small mark length of 23 nm, which is far beyond the diffraction limit. By the third-harmonic spectrum analysis of read signals, a readout spatial resolution of 19.3 nm was obtained. This spatial resolution can be used for optical disks with capacities of more than 1 TB.