Method of terminating an optical fiber
US4834493A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1987 |
| Grant date | May 30, 1989 |
| Priority date | — |
| Expiry date | Aug 26, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/2552
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fiber-optic rotation sensor particularly adapted to be placed adjacent a drill head to measure the orientation of a drill string with respect to the axis of rotation of the earth during or after drilling for minerals such as oil and gas. The analog sensor is based on a Sagnac interferometer and uses light beams counterrotating in one or more oblong circular shaped coils of optical fiber in which dual phase modulators are used to generate an AC signal to enable detection of a rotation rate output. The sensor also includes means to mechanically or electrically flip to sensitive axis of the rotation sensor to null out bias drift. If one coil is used, the flipping is in 90.degree. segments. When two coils at 90.degree. to each other are used, they are flipped 180.degree..
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.