Apodization of two-dimensional pupils with aberrations

Abstract

The technique proposed to enhance the resolution of the point spread function (PSF) of an optical system underneath defocussing and spherical aberrations. The method of approach is based on the amplitude and phase masking in a ring aperture for modifying the light intensity distribution in the Gaussian focal plane ( $$Y_{D} = 0$$ ) and in the defocussed planes ( $$Y_{D}= \pi $$ and $$Y_{D}= 2\pi $$ ). The width of the annulus modifies the distribution of the light intensity in the side lobes of the resultant PSF. In the presence of an asymmetry in the phase of the annulus, the Hanning amplitude apodizer [cos( $$\pi \beta \rho $$ )] employed in the pupil function can modify the spatial distribution of light in the maximum defocussed plane ( $${Y}_{D} = 2\pi $$ ), results in PSF with improved resolution.