Diffraction of Gaussian and Laguerre–Gauss beams from a circular aperture using the moment expansion method

International audienceA method based on the distribution theory is introduced to compute the Fresnel diffraction integral. It is applied to the diffraction of Gaussian and Laguerre–Gauss beams by a circular aperture. Expressions of the diffracting field are recast into a perturbation series describing the near- and far-field regions.