General integral expressions for on-axis spherical waves diffracted at a circular aperture

Abstract: Starting from the Fresnel–Kirchhoff diffraction integral formula and taking into consideration the inclination factor and wave-front integration, the general expressions for on-axis convergent and divergent spherical waves diffracted at a circular aperture are derived. Our results are valid for the case |f|> a, where f and a are the focal length and aperture radius, respectively. The numerical results are consistent with the experimental data of divergent spherical waves diffracted at a circular aperture. For convergent spherical waves the results are compared with those by using the Li–Wolf formula, showing the more general applicable advantage of our formulae. [Copyright &y& Elsevier]