Generating Planar Diffracting Apertures and Fraunhofer Diffraction Patterns Using Discrete Convolution and Fast Fourier Transform Techniques Part. 2

It is one of the basic principles of Fourier Optics that the field distribution in far-field or Fraunhofer diffraction pattern due to a planar diffracting aperture is proportional to the Fourier transform (FT) of field distribution in the aperture plane. The computational technique of discrete convolution is used to simulate planar diffracting apertures of varied geometry. Subsequently, the discrete Fourier transform technique is used to generate Fraunhofer diffraction patterns due to the simulated planar apertures. The basic apertures like single slits, double slits, multiple slits, rectangular and circular are generally treated in theory as a part of any wave optics undergraduate course. Some apertures with geometrical shapes, such as triangles, trapeziums, hexagons and pentagons, have been analysed in the past [1-3]. The results presented in this article(1) agree fairly well with theoretical predictions and with those reported in the literature [1-3]. The article aims to highlight the importance and ease of using computational methods in problem-solving. A computational approach has far greater flexibility and scope in exploring different aspects of a given problem compared to a corresponding analytical treatment of the same. The target group are undergraduate students of physics and engineering sciences.