Single mode optical fiber polarimetric stress sensor having optical common mode rejection
US4564289A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 31, 1984 |
| Grant date | Jan 14, 1986 |
| Priority date | — |
| Expiry date | Jul 31, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R15/248
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An instrument for measuring stress is arranged to be insensitive to stresses caused by conditions other than that of the phenomenon to be measured. The instrument employs two equal lengths of optical fibers of the kind exhibiting birefringence when stressed. Polarized light is directed into one of the optical fibers along its longitudinal axis. The two optical fibers are arranged in series with respect to the longitudinal transmission of the polarized light through those fibers. A polarization rotator is situated in the light path between the two optical fibers. The polarized light transmitted through the polarization rotator is rotated by an amount causing stresses imposed equally on the two optical fibers to have equal and opposite effects of the transmitted polarized light. The invention may be embodied to permit the measurement of acceleration, pressure, fluid flow rate, magnetic field gradient, magnetic field strength, electric field strength, electric field gradient, or any other phenomena that can be made to produce stress on an optical fiber. The invention is especially useful in differential measurement because the device measures the difference in stress imposed on the tw…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.