Fiber optic rotation sensor utilizing a magnetic shield and an optical isolator
US4671658A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 1981 |
| Grant date | Jun 9, 1987 |
| Priority date | — |
| Expiry date | Nov 9, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C19/72
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fiber optic rotation sensor, employing the Sagnac effect, comprises all fiber optic components, positioned along a continuous, uninterrupted strand of fiber optic material. The rotation sensor includes a detection system utilizing a modulator for phase modulating light waves which counterpropagate through a loop formed in the fiber optic strand. The modulator is operated at a specific frequency to eliminate amplitude modulation in the detected optical output signal. The rotation sensor is mounted in a .mu.-metal housing to shield it from the effects of ambient magnetic fields. An isolator is utilized to prevent the optical output signal from returning to the laser source. This advantageously reduces power losses in the system by eliminating the need for a coupler to couple the output signal to a detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.