Study of a Super-Resolution Optical Structure: Polycarbonate/ZnS–SiO2/ZnO/ZnS–SiO2/Ge2Sb2Te5/ZnS–SiO2

Abstract

A new super-resolution near-field optical structure was demonstrated. The structure, polycarbonate/ZnS–SiO2(130 nm)/ZnO(15 nm)/ZnS–SiO2(30 nm)/Ge2Sb2Te5(15 nm)/ZnS–SiO2(20 nm), has the ability in recording the small marks beyond the diffraction limit. At a readout power of 5 mW, the carrier to noise ratio (CNR) of more than 33 dB was measured for the recorded marks with the size of 100 nm by a digital versatile disc (DVD) tester. Transmission electron microscope (TEM) images of such structure displayed local orderly nanograins in 15 nm ZnO thin film. Ensemble effects of these ZnO nanostructures of the active layer are the key of the near-field super-resolution.