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:
Dec. 17, 1991
Filed:
Oct. 24, 1989
Serge Valette, Grenoble, FR;
Stephane Renard, Champ sur Drac, FR;
Commissariat a l'Energie Atomique, Paris, FR;
Abstract
An integrated optical device for measuring the refractive index of a fluid comprises a light guide formed on a substrate and having a guiding layer for carrying light beams, inserted between a lower layer and an upper layer having refractive indices below that of the guiding layer. The device includes an interaction measurement zone of the light guide for coming into contact with the fluid, the upper layer at the measurement zone having a thickness less than the penetration distance of the evanescent wave of the guided light beam. Outside the interaction zone, that upper layer has a thinckness greater than the penetration distance of the same evanescent beam. The device also has an interferometric optical system at least partly formed in the light guide and having a reference optical circuit and a measurement optical circuit including the measurement zone, for measuring the phase shift introduced by an effective index change of the guided mode due to the fluid.