Augustin-Jean Fresnel was a French civil engineer and physicist whose research in optics led to the almost unanimous acceptance of the wave theory of light, fully supplanting Newton's corpuscular theo
Portrait of "Augustin Fresnel" from the frontispiece of his collected works, 1866
Monument to Augustin Fresnel on the facade of his birthplace at 2 Rue Augustin Fresnel, Broglie (facing Rue Jean François Mérimée), inaugurated on 14 September 1884. The inscription, when translated, says: "Augustin Fresnel, engineer of Bridges and Roads, member of the Academy of Sciences, creator of lenticular lighthouses, was born in this house on 10 May 1788. The theory of light owes to this emulator of Newton the highest concepts and the most useful applications."
Nyons, France, 19th century, drawn by Alexandre Debelle (1805–1897)
First-order rotating catadioptric Fresnel lens, dated 1870, displayed at the Musée national de la Marine, Paris. In this case the dioptric prisms (inside the bronze rings) and catadioptric prisms (outside) are arranged to give a purely flashing light with four flashes per rotation. The assembly stands 2.54 metres tall and weighs about 1.5 tonnes.
A Fresnel lens is a type of composite compact lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections.
First-order group-flashing Fresnel lens, on display at the Point Arena Lighthouse Museum, Point Arena Lighthouse, Mendocino County, California. The three dioptric panels (inside the brass rings) and three catadioptric panels (outside) are partly split in two, giving three double-flashes per rotation.
Close-up view of a flat Fresnel lens shows concentric circles on the surface.