Imaging beyond the diffraction limit by employing a super-oscillatory filter

In this paper, we propose an approach to overcome the well-known “diffraction limit” when imaging sources at several wavelengths away. We employ the superdirective antenna´s concepts to design a super-oscillatory filter (SOF) based on the properties of Tschebyscheff polynomials. The SOF is applied to the reconstructed image based on the back-propagation algorithm. We demonstrate the capability of this approach when imaging two sources spaced at 5λ away.