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. 12, 1989
Filed:
Mar. 14, 1988
John W Hicks, Northboro, MA (US);
Other;
Abstract
A fiber laser differential sensor measures changes in a selected parameter by means of several single fiber laser sensors which are sensitive to both changes in the selected parameter and changes in other parameters which are not of interest. Each single sensor is comprised of two fiber lasers which are each optically coupled to a third fiber so that energy is exchanged between each of the laser fibers and the third fiber. The single sensor structure is arranged so that it operates with least loss when the two lasers oscillate at a common frequency. The common frequency is, in turn, sensitive to changes in the optical path length of either of the fiber lasers. The single sensors are arranged so that their optical path lengths change in response to changes in the selected and other parameters. The outputs of the sensors are beat together to eliminate variations due to parameters other than the desired parameter.