Geometric optical transfer function and pupil sampling patterns

Abstract

We have studied several pupil sampling patterns for calculating the optical transfer function corresponding to actual non-diffraction limited optical imaging systems, in the low range of spatial frequencies, i.e., where the geometric approach is valid, by means of the Fourier Transform of the spot diagram. Then, we have compared the diffraction and the geometric optical transfer functions to ascertain if there is a sampling pattern that accurately calculates the latter within a 5% of difference, and having less number of sampling points. The results show that, overall, the non redundant spiral pupil sampling provides the best choice. This could be valuable when optimizing or characterizing optical imaging systems in the non-diffraction limited range by harnessing raytracing.