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. 14, 1992
Filed:
Oct. 31, 1990
Applicant:
Inventors:
Jean-Pierre Monchalin, Montreal, CA;
Rene Heon, McMasterville, CA;
Assignee:
National Research Council Canada, Ottawa, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356352 ; 356358 ; 73657 ;
Abstract
A laser ultrasound detection technique which is insensitive to laser intensity fluctuations, perturbation at the object surface and the like is disclosed. The invention consists of two substantially identical interferometers of the Fabry-Perot type or such an interferometer with a birefringent element in its optical cavity. The interferometers have resonance frequencies higher and lower than the laser frequency so that noises can be cancelled out by signal processing.