Numerical calculation of Kirchhoff integral in approximation of Fresnel diffraction

A development of Hopkins’ technique for numerical solution of Kirchhoff integral used to derive approximate solution of the diffraction problem, is suggested. The technique employs the quadratic terms of this integral series expansion, and thus realises a Fresnel diffraction approximation. The numerical experiment results are also presented. Analysis of the made assumptions allows to find the applicability limits of the technique.