Low-noise fiber optic sensor utilizing a laser source

US7911619B2 · kind B2 · utility

Assignee

• The Board of Trustees of the Leland Stanford Junior University · US

Inventors

• Stéphane Blin · Palo Cedro, US
• Michel J. F. Digonnet · Palo Alto, US
• Gordon S. Kino · Stanford, US
• Seth Lloyd · Stanford, US

Key dates

• Filing date: Nov 14, 2008
• Grant date: Mar 22, 2011
• Expiry date: Jul 30, 2029

Classification

• Technology area (CPC G): Physics
• CPC primary: G01C19/721
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A fiber-optic sensor includes an optical fiber coil and a laser source optically coupled to the coil. Light from the source is transmitted to the coil as a first signal propagating along the coil in a first direction and a second signal propagating along the coil in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the coil to generate a third signal. The laser source is frequency-modulated or can have a coherence length longer than a length of the coil.