Numerical simulation of electromagnetic propagation in super-resolution near-field structure

High density optical data storage based on near-field optical super resolution is a new technique that attracts great attention in recent years. Super-resolution near-field structure (Super-RENS), glass/SiN/Sb/SiN, a promising structure for near field ultrahigh-density optical storage, has been proposed and investigated since 1998. The recording mark size is a few tens of nanometers, far beyond the diffraction limit of the traditional optics. The mechanism of this Super-RENS including the working principle of the non-linear optical layers and the size reduction of the recording marks has not been clearly understood. In this paper, the electromagnetic propagation in Super-RENS is numerically simulated. The results show that the recording mark size is reduced and the peak intensity increased by the Super-RENS. The mechanism of the phenomenon is discussed.