Augustin Jean Fresnel (10.05.1788-14.07.1827) was a French physicist and a member of the Paris Academy of Sciences (1823). He was born in Broglie. He graduated from the École Polytechnique (1806) and the École des Ponts et Chaussées (1809) in Paris. He worked as an engineer repairing and building roads in various départements of France, and from 1817 at the École Polytechnique.
His work concerned physical optics. As early as 1811, under the influence of É. Malus, he began to study physics on his own and soon began experimental research in optics. He rediscovered the principle of interference in 1815 and supplemented the known principle of Huygens by introducing (1816) the notion of the coherence of elementary waves and their interference (the Huygens — Fresnel principle). Proceeding from these two principles, he developed in 1818 the theory of the diffraction of light. He was the first to consider diffraction by an edge and by a circular aperture. He performed experiments with bimirrors (1816) and biprisms (1819) on the interference of light which became classics. He studied the interference of polarised rays. He proved in 1821 the transverse nature of light waves (he arrived at the idea of transversality in 1819 independently of T. Young). He discovered in 1823 the elliptical and circular polarisation of light. On the basis of wave concepts he explained chromatic polarisation, the rotation of the plane of polarisation of light and double refraction. He established (1823) the laws of reflection and refraction of light at a plane stationary interface between two media (the Fresnel formulas). Together with T. Young he is the creator of wave optics. He invented a number of interference instruments (the Fresnel mirrors, the Fresnel biprism, the Fresnel lens).
He studied the problem of the influence of the Earth's motion on optical phenomena, thereby beginning (1818) the optics of moving bodies. He put forward the idea of partial ether drag and derived the coefficient of drag of light by moving bodies (gave a formula for the change in the speed of light). However, these conclusions of his found their explanation only in the theory of relativity.
A Fellow of the Royal Society (1825). The B. Rumford Medal.