Interferometer with a looped or straight optical fiber

US11885622B2 · kind B2 · utility

Assignee

• EXAIL · FR

Inventors

• Eric Ducloux · Rueil-Malmaison, FR
• Cedric Molucon · Poissy, FR
• Herve Lefevre · Paris, FR

Key dates

• Filing date: Apr 14, 2020
• Grant date: Jan 30, 2024
• Expiry date: Aug 17, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R15/246
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A fiber-optic interferometer is designed to receive and propagate a first single-mode wave along a first optical path and, respectively, a second single-mode wave along a second optical path, the second optical path being the reverse of the first optical path, and to form a first output wave and, respectively, a second output wave, having a modulated phase difference Δϕm(t). According to the invention, the modulated phase difference Δϕm(t) is equal to sum of a first periodic phase difference Δϕπ(t) having a level equal to ±π, a second periodic phase difference Δϕalpha(t) having a level equal to ±alpha and a third periodic phase difference Δϕbeta(t) having a variable level between −beta and +beta, said modulated phase difference Δϕm(t) comprising per modulation period T at least eight modulation levels among twelve modulation levels and said modulated phase difference between such that: Δϕm(t+T/2)=−Δϕm(t).