On the propagation and interference of elliptical wavefronts

One of the most intriguing aspects of light is its dual nature, simultaneously exhibiting raylike and wavelike behavior. This ray–wave duality lies at the heart of optics, bridging geometric and wave descriptions. In this work, we investigate elliptical wavefronts, which arise as anticaustics (that is, virtual wavefronts of zero path difference) generated by the refraction of light from of a point source at a planar interface. The associated rays, normals to the ellipse, recall a classical problem first addressed by the Greek geometer Apollonius of Perga. Revisiting this construction within the framework of modern optics, we extend the analysis to include the superposition of elliptical wavefronts, thereby enriching the theoretical description of interference phenomena.