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:
Mar. 19, 1991
Filed:
Dec. 01, 1989
Kazunori Nakamura, Kanagawa, JP;
The Furukawa Electric Co., Ltd., Tokyo, JP;
Abstract
A sensing system using optical fibers having loss characteristics subject to variations of a signal light wave as a pumping light wave with a wavelength different from that of a pumping light wave is coupled into said optical fiber. Unlike conventional OTDRs that utilizes a light back scattering in an optical fiber, a sensing system using optical fibers according to the invention utilizes the light passing through an optical fiber as a detected signal in order to enhance the efficiency and effectiveness of the system and, therefore, it has a significantly improved S/N ratio and a dynamic range of measurement as compared with conventional OTDRs. Moreover, continuous light may be used for the signal light wave (detected signal) to increase the rate of light emission for detection and to reduce the time required for measurement.