— a set of diffraction phenomena, considering them not neglect the curvature of the wave surface incident and diffracted (or just diffracted) waves. F. d. Observed in cases where the light source and the screen (or the screen only) are at finite distances from obstacles that causes diffraction. When F. d. The screen goes «diffraction image» noise. Investigated in $1815$ France. A. scientist Jean Fresnel $(1788 - 1827)$ (see. as Diffraction of light).