Remotely readable fiber optic compass
A remotely readable compass is described consisting of: a magnet rotatably mounted in a compass body so as to be freely rotatable with respect to the compass body, a rotatable sheet polarizer affixed to the magnet so as to be rotatable with respect to the compass body with the magnet about a common axis of rotation; first and second excitation optical fibers affixed to the compass body and terminating adjacent the rotatable sheet polarizer so as to direct light propagated through the fibers onto the rotatable sheet polarizer, and first and second return optical fibers affixed to the compass body and positioned respectively opposite the rotatable sheet polarizer from the excitation fibers, so as to receive light which is emitted from the first and second excitation fibers and transmitted through the rotatable sheet polarizer; and first and second fixed sheet polarizers, the first fixed sheet polarizer being affixed to the compass body so as to be optically interposed between the first excitation fiber and the first return fiber, the second fixed sheet polarizer being affixed to the compass body so as to be interposed between the second excitation fiber and the second return fiber, the fixed sheet polarizers having optical axes which are oriented substantially orthogonally with respect to one another; whereby the orientation of the magnet with respect to the compass body can be determined by transmitting two light beams through the excitation fibers, through the fixed sheet polarizers and through the rotatable sheet polarizer, and measuring the ratio of the intensities of the resulting light beams received in the return fibers.
- Assignee:
- Dept. of Energy, Washington, DC
- Patent Number(s):
- US 4577414
- OSTI ID:
- 5879170
- Resource Relation:
- Patent File Date: Filed date 30 Apr 1985
- Country of Publication:
- United States
- Language:
- English
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