Monitoring for disturbance of optical fiber
US9207168B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 2013 |
| Grant date | Dec 8, 2015 |
| Priority date | — |
| Expiry date | Feb 25, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/332
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Problems of excessive fading in systems for monitoring single-mode optical fiber for disturbances are addressed by launching into the fiber polarized light having at least two different predetermined launch states of polarization whose respective Stokes vectors are linearly-independent of each other; downstream from the first location, receiving the light from the fiber; analyzing the received light using polarization state analyzer having at least two different analyzer states of polarization that are characterized by respective Stokes vectors that are linearly-independent and detecting the analyzed light to provide corresponding detection signals; deriving from the detection signals measures of changes in polarization transformation properties of the fiber between different times that are invariant under a non-reflective unitary transformation on either the launch states or the detection states; and, on the basis of predefined acceptable physical disturbance criteria determining whether or not the measures are indicative of a reportable physical disturbance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.