Describes an Apple computer program (listing available from author) which simulates Fraunhofer and Fresnel diffraction using vector addition techniques (vector chaining) and allows user to experiment with different shaped multiple apertures. Graphics output include vector resultants, phase difference, diffraction patterns, and the Cornu spiral…

A computer program, making use of interactive computer graphics, has been developed to help students become fluent in the mathematical procedures needed to understand concepts of addition of waves. Background theory, use of the program, and technical and educational features of the program (written in Fortran) are discussed. (Author/JN)