— a set of diffractive effects when considering which neglect the curvature of the wave surface incident and diffracted waves. F. d. Observed in cases where the light source and the screen is infinitely remote from obstacles, at which the diffraction. When F. d. The screen is obtained “diffraction picture” of the light. Research in $1814 - 1815$ it. I. optician Fraunhofer $(1787 - 1826)$ (see. as Diffraction of light).