Superresolution performance of an absorbing glass positive lens element

Abstract

Superresolution performance of a plano-convex lens made of absorbing glass is analyzed numerically. It was found that a reduction of the radius of the Airy disk depends solely on the center transmittance of the lens (a zero edge thickness is assumed) for any reasonable ratio of radius of curvature of the convex surface and the lens radius. The modest decrease in the size of the central diffraction peak is followed by a large decrease of its energy content and a rapid brightening of the diffraction rings. The most that can be achieved with such a lens is a reduction of the radius of the Airy disk to 71% of the corresponding clear aperture value, followed by approximately 78% of the energy being diverted into diffraction rings.