Diffraction of Gaussian beam by apertures and geometrical theory of diffraction

An application of geometrical theory of diffraction and physical optics method to solving scattering problem of Gaussian beam by circular aperture in a screen is discussed in the case of the short-wave approximation. An asymptotic analysis is developed to describe solution for the wave transmitted through the hole in the near-filed zone. Both asymptotic solutions for the point source and Gaussian beam diffraction were tested numerically to compute the transmitted wave field intensity versus the data obtained by the well-known approximation of the plane wave decomposition.