Static optical recording properties of super-resolution near-field structure with bismuth mask layer

Super-resolution near-field structure (super-RENS) with bismuth (Bi) mask layer (Bi-super-RENS) is reported for the first time in this paper. Bi thin films with various thicknesses were studied by atomic force microscopy and grazing incident X-ray diffraction. Static optical recording tests with and without super-RENS were carried out using 650 nm semiconductor laser at recording power of 14 mW and 7 mW with pulse duration of 100 ns. The recording marks were observed by scanning electron microscopy and high-resolution optical microscopy with a CCD camera. Results showed that the Bi mask layer can also concentrate energy into the center of a laser beam at low laser power similar to the traditional Sb mask layer. Moreover, a (ZnS)(80)(SiO2)(20) protection layer performed better than the SiN protection layer in the Bi-super-RENS. The direct observation of laser-recording marks may help better understand the working mechanism of the super-RENS, super-resolution ablation, and other nonlinear switch phenomena.