Fourier Optics and near-field superlens

Fundamental Fourier optics is applied to metallic near-field superlens, whose transfer function is computed with the transfer matrix, the Surface Plasmon Polariton (SPP) resonance and the SPP waveguide theory. However, as the object nano-structure consists of feature nano-slits, nano-holes and nano-particles, which are as the basic object elements to scatter the light, especially for metal objects the electrical dipoles are induced, the object field must be computed by scattering theory or by numerical solution of the Maxwell's equation, so that the point spread function as the Fourier transform of the transfer function is less likely useful to obtain the image. The superlens is designed and optimized based on the transfer function. Improvement in the transfer function can improve significantly the image quality. However, the real image of the near-field superlens should be computed with numerical simulation using the FDTD method.