Methods of and systems for optical fiber sensing
US4904050A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1988 |
| Grant date | Feb 27, 1990 |
| Priority date | — |
| Expiry date | Aug 31, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/4469
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical fiber sensing system for detecting intrusion of optical fiber or optical fiber cables includes an interferometric arrangement. Two ports (28, 30) of a four port splitter (25) are connected to a source (26) of optical power such as a laser, for example, and to a detector (32). The other two ports (46, 48) are connected to ends of a length (50) of monitoring optical fiber. An input signal to the splitter is split with one subsignal being directed in one direction around the length of optical fiber which serves as a common path between the two ports. The other signal is caused to travel around the common path in an opposite direction. The split signals are recombined in the splitter and their phase difference measured as a detectable pattern by the detector. Should there be intrusion of the optical fiber or a cable containing the monitoring optical fiber, the pattern which is detected will change a significant amount.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.