Fiber analysis method and apparatus
First Claim
1. A method for analyzing a buried underground optical fiber comprising the steps of:
- splitting an optical signal into a pair of sub-signals;
injecting each sub-signal into an end of the fiber so that the sub-signals traverse the fiber in opposite directions to emanate from ends into which the each sub-signal were injected;
combining the sub-signals emanating from the fiber ends into a single recombined beam; and
measuring the characteristics of the recombined beam,WHEREIN THE IMPROVEMENT COMPRISES;
receiving stress on the fiber that varies characteristics of the re-combined beam;
comparing the measured characteristics of the re-combined beam to reference values representing identifiable fiber conditions; and
establishing a fiber condition in accordance with a match between one of said identifiable fiber conditions and the measured recombined beam characteristics.
1 Assignment
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Accused Products
Abstract
A Fiber Analysis System (10) detects threats to a buried underground fiber (10) by delivering two optical sub-signals, split from a single beam, into opposite ends of the fiber so the sub-signals traverse the fiber in opposite directions. The sub-signals are recombined into a beam whose characteristics are detected by a detector (24). The output signal of the detector (24) is compared by a processor (26) to different reference values stored in a data base (28) representing different detector output signals corresponding to different fiber conditions. By matching the detector output signal to a reference value associated with a particular fiber condition, the processor can determine whether a potential threat exists. By inducing a sequence of known vibrations (tones) inn the fiber at spaced locations along a generally orthogonal to the fiber (12), the processor (26) can establish the location of the fiber by comparing the detector output signal to a reference signals corresponding to the known tones to determine which one was received in the shortest time.
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Citations
21 Claims
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1. A method for analyzing a buried underground optical fiber comprising the steps of:
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splitting an optical signal into a pair of sub-signals; injecting each sub-signal into an end of the fiber so that the sub-signals traverse the fiber in opposite directions to emanate from ends into which the each sub-signal were injected; combining the sub-signals emanating from the fiber ends into a single recombined beam; and measuring the characteristics of the recombined beam, WHEREIN THE IMPROVEMENT COMPRISES; receiving stress on the fiber that varies characteristics of the re-combined beam; comparing the measured characteristics of the re-combined beam to reference values representing identifiable fiber conditions; and establishing a fiber condition in accordance with a match between one of said identifiable fiber conditions and the measured recombined beam characteristics. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for analyzing a buried underground optical fiber, comprising:
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a light source for generating a beam of light; a four-port splitter for splitting the beam of light into two optical sub-signals injected into opposite ends of the fiber to traverse the fiber in opposite directions for receipt at the splitter which recombines the sub-signals into a combined beam; and a detector for detecting characteristics of the combined beam, WHEREIN THE IMPROVEMENT COMPRISES; a data base containing reference values representing beam characteristics corresponding to different fiber conditions; and a processor for comparing the reference values in the data base to the detected beam characteristics to find a match therebetween to establish a fiber condition in accordance with said match. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification