About the Project
9 Airy and Related Functions

Sidebar 9.SB2: Interference Patterns in Caustics

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A thin beam of light refracted by an irregularity in bathroom-window glass produces this image on a distant screen. The bright sharp-edged triangle is a caustic, that is a line of focused light. The oscillating intensity of the interference fringes across the caustic is described by the Airy function.