Interferometrical methods have long been a very precise way to measure optical wavelength. The development, since now almost 20 years, of highly stabilized laser sources has permit to undertake interferometric measurements of wavelength ratios to an accuracy level which was not accessible to the wavelength standard of the previous definition of the meter based on the value of the krypton orange line. Since October 20th 1983 the meter is defined as following : "Le metre est la longueur du trajet parcouru par la lumiere dans le vide en une duree de 1/299792458 de seconde."

Date Published: 1 January 1987
PDF: 2 pages
Proc. SPIE 0813, Optics and the Information Age, (1 January 1987); doi: 10.1117/12.967257

Published in SPIE Proceedings Vol. 0813:
Optics and the Information Age
Henri H. Arsenault, Editor(s)