Surface plasmon effects on the far-field signals of AgO_x-type super resolution near-field structure

A super-resolution near-field structure (Super-RENS) of AgO_x type could perform the task of high-density near-field optical recording in a more feasible way. To further explore the optical resolution and controllability of super-RENS disks, the near-field and far-field optical properties of the AgO_x-type super-RENS embedded with random silver nanoparticles and nano cavities of different densities were studied using finite-difference time-domain simulations. The random nanostructures yielded super-resolution capability, but the surface plasmon effects generated by the random metallic nanoparticles significantly enhanced the far-field signals. A simplified Fourier optical theory was proposed to understand the relationship between the enhanced near field of random nanostructures and the super-resolution capability in the far field.