Who were Fabry and Pérot?

In 1897 Charles Fabry and Alfred Pérot published their most important article on what we now call the Fabry–Pérot interferometer. Despite the great importance of this instrument for present-day research in physics and astrophysics, its inventors are almost completely unknown to most physicists. This article presents brief accounts of the life and work of Fabry and Pérot, who at the beginning of the twentieth century were highly regarded by physicists throughout the world for their contributions to optics and spectroscopy. Later they also made many important contributions to astrophysics, including Fabry’s 1913 discovery (with Henri Buisson) of the ozone layer in the Earth’s atmosphere.