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:
Apr. 11, 2000
Filed:
Jan. 29, 1999
Ian Arthur White, Dunwoody, GA (US);
Lucent Technology Inc., Murray Hill, NJ (US);
Abstract
An optical fiber sensing system (20) applies spectral analysis to time-varying disturbances in the output optical power from a Sagnac interferometer. In particular, harmonically related null frequencies in the spectrum (402) of the output optical power from the Sagnac interferometer are used to uniquely determine the location of a disturbance along a fiber cable (50). An optical signal having relatively high coherence is fed into a splitter (25), which creates a pair of subsignals that are sent in opposite directions around a common optical path. The splitter is effective to recombine the subsignals after they have traveled around the common path. The location of the disturbance is determined by the formula: ##EQU1## z is the distance between the locations of the disturbance and the splitter;