Rpm measuring device utilizing an optical fiber coil and winding method for making the coil

US4781461A · kind A · utility

Assignee

• Teldix GmbH · DE

Inventors

• Klaus U. Baron · Heidelberg, DE
• Eberhard Kiesel · Trier, DE

Key dates

• Filing date: Sep 11, 1986
• Grant date: Nov 1, 1988
• Expiry date: Sep 11, 2006

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B6/4457
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A rpm-measuring device including a closed light path comprising a coil formed of a plurality of winding layers of an optical fiber having first and second ends; a beam splitter connected to the first and second ends; an arrangement for passing two light beams in opposite directions through the coil by applying the two light beams to the first and second ends, respectively, and an arrangement for superposing the two light beams subsequent to their passage through the coil and for evaluating a phase-shift based on the Sagnac-effect. The distance of the light path between the first end and any selected first location of the optical fiber is identical to the distance of the light path between the second end and a second location of the optical fiber. The selected first location and the second location are situated in immediately adjoining two windings belonging to two separate, immediately adjoining winding layers, whereby the two light beams propagate at all times in immediately adjoining two windings belonging to two separate, immediately adjoining winding layers.