Method and apparatus measuring absolute rotation

US4549806A · kind A · utility

Assignee

• Licentia Patent-Verwaltungs-GmbH · DE

Inventors

• Peter Marten · Heidelberg, DE
• Klaus Petermann · Wedel, DE

Key dates

• Filing date: Sep 30, 1982
• Grant date: Oct 29, 1985
• Expiry date: Sep 30, 2002

Classification

• Technology area (CPC G): Physics
• CPC primary: G01C19/72
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Method for measuring absolute rotation with the aid of a light conductive fiber ring interferometer including a light source, a beam dividing arrangement, a light path formed by a light conductive fiber coil, an optical phase modulator which is disposed in the light path and which modulates the light circulating in the light path with a periodic, optical phase modulation at a fundamental frequency f.sub.0, and a photodetector for providing an electrical output signal. The light circulating in the light path or an electrical output signal from the photodetector is modulated with at least one mixing frequency f.sub.2 in a manner such that an electrical evaluation signal results which has an evaluation frequency f.sub.1 which is smaller than that of the fundamental frequency f.sub.0 and which is evaluated to determine the absolute rotation of interest.