Fiber-optic current sensor
US6636321B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 4, 2001 |
| Grant date | Oct 21, 2003 |
| Priority date | — |
| Expiry date | Jun 18, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R15/246
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fiber-optic current sensor has a reflection interferometer having a fiber-optic supply lead and a coil-shaped optical sensor fiber, the sensor fiber being connected with a first end to the fiber-optic supply lead, and being provided at a second, free end with a reflector. The fiber-optic supply lead has two fiber arms, which interconnect a detector-side and a sensor-side polarization-maintaining coupler. A phase modulator for modulating differential phases of two polarized waves propagating in the supply lead fiber is arranged in one of these two fiber arms, in which it modulates the differential phase of two waves polarized parallel to one another. Moreover, the sensor can change the direction of polarization in one of the two fiber arms, such that optical waves with orthogonally linear polarizations propagate in a segment of the supply lead fiber adjoining the sensor-side coupler. As a result, the advantages of the reflection interferometer can be combined with those of a Sagnac interferometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.