Enhanced two-point resolution using optical eigenmode optimized pupil functions

Abstract

Pupil filters have the capability to arbitrarily narrow the central lobe of a focal spot. We decompose the focal field of a confocal-like imaging system into optical eigenmodes to determine optimized pupil functions, that deliver superresolving scanning spots. As a consequence of this process, intensity is redistributed from the central lobe into side lobes restricting the field of view (FOV). The optical eigenmode method offers a powerful way to determine optimized pupil functions. We carry out a comprehensive study to investigate the relationship between the size of the central lobe, its intensity, and the FOV with the use of a dual display spatial light modulator. The experiments show good agreement with theoretical predictions and numerical simulations. Utilizing an optimized sub-diffraction focal spot for confocal-like scanning imaging, we experimentally demonstrate an improvement of the two-point resolution of the imaging system.