The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 08, 1985
Filed:
Mar. 27, 1984
Gilbert L Bourdet, Bures sur Yvette, FR;
Michel A Franco, Paris, FR;
Agence Nationale de Valorisation de la Recherche, Paris, FR;
Abstract
The apparatus and method include adjusting two single frequency lasers to separate longitudinal modes of an interferometer, the plates of which are separated by a distance to be measured. A rough estimate of the distance is made using a tape measure or the like. The rough estimate, together with the frequency distance (.DELTA.F) of the lasers adjusted to the longitudinal modes of the interferometer is used to solve the equation: ##EQU1## where c is the speed of light and L.sub.1 is the rough estimate. The parameter k then calculated by rounding k.sub.1 to the nearest integer and the accurate distance L is calculated according to the equation: ##EQU2##