Evanescent signal detection and enhanced resolution with random silver nanoparticles.

Inspired by the subwavelength resolution capability of the super-resolution near-field structure, a simplified optical structure was proposed to investigate the complicated near-field optical interactions between random silver nanoparticles and evanescent waves from a zeroth-order grating. The simplified structure consisted of a glass thin film embedded with random silver nanoparticles on a zeroth-order glass grating. The near-field and far-field optical properties of this structure were investigated by the finite-difference time-domain (FDTD) numerical simulations and the optical resolution beyond diffraction limit was demonstrated.