Fresnel and far-field diffraction due to an elliptical aperture

Based on the Hopkins [ Proc. Phys. Soc. London Sect. B70, 1002 ( 1957)] algorithm, theoretical and experimental investigations of the Fresnel and far-field diffraction of a coherent light beam that is due to an elliptical aperture with the axial ratio ∊ between 0 and 1 are presented. Perspective plots of the intensity distribution patterns and their cross section across the major and minor axes are generated with the help of an IBM-370/168 computer. Experimental results presented in photographs and in densitograms are compared with the theoretical prediction. A close agreement between them has been obtained. Also given are the plots of the intensity distribution along the optical axis.