Fabry-Pérot's interferometer (1898)

 

Copyright: Inventaire générale, Direction du Patrimoine, Ministère de la Culture
 

Presented at the 1900 World Fair in Paris, this device uses spectral interference and consists of two flat and parallel beam splitters. Designed by Charles Fabry and Alfred Perot, and crafted by Amédée Jobin, it measures luminous spectra with a very high resolution. This type of interferometer was used to determine the standard meter, investigate the hyperfine structure of atoms, and manufacture engraved gratings, particularly to control the position of the cutting diamond.