Light transformations in metallo-dielectric nanolayers

Sub-wavelength imaging is an important beam transformation operation obtained with metallo-dielectric multilayers at visible wavelengths. However, other spatial transformations may be realised in similar structures as well. They range from imaging and differentiation to beam splitting and for two-dimensional signals also to polarisation coupling, as well as more sophisticated operations. Such transformations may be described as linear filtering of the optical spatial spectrum with a filter function of the wavelength-order size. Our numerical analysis is based on the plane-wave decomposition, transfer matrix method, and the modeling of the vectorial pulse spread function.