The Fresnel lens is a lens developed from the shape of a converging lens, which is used in motion detectors, as well as in lighting and projection technology.
Fresnel lenses have a step-shaped structure, are extremely flat and therefore correspondingly light. The individual stages of the Fresnel lens follow the spherical lens shape. As with the lens shape, the refraction of light occurs as a function of the refraction angles between the two surface sides.
The Fresnel lens is named after the French physicist Augustin Fresnel (1788 to 1827) and was first used in lighthouses for the beacon. It can be found in stage spotlights and in spotlights with adjustable beam angle, in LED lights and projectors.