Three Zone Asymmetric Pupil Filter for Increasing Two-point Resolution of Optical Imaging Systems

ABSTRACT

In the present study, influence of three zone asymmetric apodizer on the resolution of composite image of two object points with given intensity ratio ‘c’ has been investigated. The proposed pupil function and its transmittance is formulated and studied. Fourier analytical properties of three zone aperture systems are studied by applying the modified sparrow criterion. The results are discussed in terms of sparrow limits obtained as a function of the degree of coherence of the illumination, intensity ratio of two object points and apodization parameters. Additionally, a test for the resolvability of the point sources from various set of observations is presented. It is established that for certain cases of illumination, the presence of amplitude and phase apodizer leads to an improvement in the resolution of optical imaging systems. The dependence of these characteristics on apodization controlling parameters is studied and reported.

Keywords:

Asymmetric apodization , Two-point resolution, sparrow resolution limit, three zone pupil filter, diffraction.