Intrusion detection system for use on single mode optical fiber using a polarimeter
US7206469B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 15, 2005 |
| Grant date | Apr 17, 2007 |
| Priority date | — |
| Expiry date | Jun 15, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/276
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A telecommunications optical fiber is secured against intrusion by detecting manipulation of the optical fiber prior to an intrusion event. This can be used in a non-locating system where the detection end is opposite the transmit end or in a locating system which uses Fresnel reflections and Rayleigh backscattering to the transmit end to detect and then locate the motion. The Rayleigh backscattering time sliced data can be stored in a register until an intrusion event is detected. The detection is carried out by a polarization detection system which includes an optical splitter which is manufactured in simplified form for economic construction. This uses a non-calibrated splitter and less than all four of the Stokes parameters. It can use a polarimeter type function limited to linear and circular polarization or two linear polarizers at 90 degrees.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.