journal of kerbala university

In this research , the effect of Gaussian spatial filter which has coefficient of normative deviation (a) in different value (a=0.25,0.5,0.75,1) has been studied on point spread function )PSF (whereas the equation of )PSF (which contain the term which represent the gausian filter has been derived for the ideal optical system or contain focus error (W20=0.25λ,0.5λ), the results have been showed that the lower value of coefficient of normative deviation for Gaussian spatial filter leads to increase the intensity in the formed image and the reduced the effect of aberrations on the distribution of the intensity in the image plane , also the effect of aperture shape has been studied on the formed image for the system contains Gaussian spatial filter, the aperture is used in different shapes (square, rectangle (vertical and horizontal)),the results showed that the rectangle horizontal aperture give the best resolution from the other at the perfect system and best distribution of intensity in the image plane at system contain focus error (W20=0.25λ,W20=0. 5λ) from the other.