Polarimetric fibre sensor
US4642458A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 1985 |
| Grant date | Feb 10, 1987 |
| Priority date | — |
| Expiry date | Sep 5, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K11/32
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A polarmetric fiber sensor comprises a lead fiber (1) and a shorter length of sensing fiber (2). Both fibers comprise higly birefringent optical fiber having orthogonal eigen modes and are spliced together with their eigen modes mutually rotated by 45.degree.. The sensing fiber (2) has a reflective distal end (6). Linearly polarized light from a laser source (3) is launched into one mode of the lead fiber (1) and light reflected from the distal end of the sensing fiber is recovered from the other mode of the lead fiber via a beam splitter (7) and photodiode (8). The resulting electrical signal produced by the photodiode (8) corresponds to the modal birefringence of the sensing fiber (2) and changes in this birefringence are monitored by processing means (9) to detect changes in a physical parameter sensed by the sensing fiber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.