The influence of a polygonal local defect on the structure of Fraunhofer diffraction pattern of a circular aperture

摘要

A method is proposed, which explains the scheme of forming a structure of diffraction pattern (DP) of a circular aperture in the presence of a single polygonal local defect by means of the system of patterns and terms used in geometric diffraction theory (GDT). The DP intensity modulation has a clearly pronounced local character, zones of influence of diffraction waves of defect edges (bright "beams") and darker zones of influence of waves of angular defect points (between "beams") are detected. Lines along which the minimum intensity distributions are grouped (DP structure lines) are second-order curves, the lines are local: correspond to the DP structure within "own" zone. The highest point group of symmetry for DP of an aperture with a non-central defect is 2m, the lowest is 2.