Method for calculating the scattering function of an optical system point

The article presents a mathematical apparatus for precise calculation of the three-dimensional point spread function (PSF) of a high-aperture optical system. The proposed method is based on the Huygens-Fresnel principle: a spherical wave on the three-dimensional surface of the exit pupil is considered as result of the superposition of elementary secondary point radiation sources. These point sources emit coherent electromagnetic waves with a spherical wave front. They form a certain distribution of generalized complex amplitudes in three-dimensional space near the focus point. This distribution is used to calculate the intensity distribution in the focus area of ​​the optical system, which is the PSF. The article presents the results of PSFcalculations and their comparative.